Starboard Value SC 13D/A CALGON CARBON Corp

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

(Rule 13d-101)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT

TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO

§ 240.13d-2(a)

(Amendment No. 6 )1

Calgon Carbon Corporation

(Name of Issuer)

Common Stock, par value $0.01 per share

(Title of Class of Securities)

129603106

(CUSIP Number)

JEFFREY C. SMITH

STARBOARD VALUE LP

830 Third Avenue, 3rd Floor

New York, New York 10022

(212) 845-7977

STEVE WOLOSKY, ESQ.

OLSHAN FROME WOLOSKY LLP

Park Avenue Tower

65 East 55th Street

New York, New York 10022

(212) 451-2300

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

May 2, 2014

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box ¨.

Note:  Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits.  See § 240.13d-7 for other parties to whom copies are to be sent.

_______________

1              The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP NO. 129603106

1	NAME OF REPORTING PERSON STARBOARD VALUE LP
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION DELAWARE
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 3,245,000
	8	SHARED VOTING POWER - 0 -
	9	SOLE DISPOSITIVE POWER 3,245,000
	10	SHARED DISPOSITIVE POWER - 0 -
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,245,000
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 6.0%
14	TYPE OF REPORTING PERSON PN

2

CUSIP NO. 129603106

1	NAME OF REPORTING PERSON STARBOARD VALUE AND OPPORTUNITY MASTER FUND LTD
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION CAYMAN ISLANDS
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 1,811,556
	8	SHARED VOTING POWER - 0 -
	9	SOLE DISPOSITIVE POWER 1,811,556
	10	SHARED DISPOSITIVE POWER - 0 -
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,811,556
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 3.4%
14	TYPE OF REPORTING PERSON CO

3

CUSIP NO. 129603106

1	NAME OF REPORTING PERSON STARBOARD VALUE AND OPPORTUNITY S LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION DELAWARE
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 432,558
	8	SHARED VOTING POWER - 0 -
	9	SOLE DISPOSITIVE POWER 432,558
	10	SHARED DISPOSITIVE POWER - 0 -
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 432,558
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) Less than 1%
14	TYPE OF REPORTING PERSON OO

4

CUSIP NO. 129603106

1	NAME OF REPORTING PERSON STARBOARD VALUE AND OPPORTUNITY C LP
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION DELAWARE
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 210,547
	8	SHARED VOTING POWER - 0 -
	9	SOLE DISPOSITIVE POWER 210,547
	10	SHARED DISPOSITIVE POWER - 0 -
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 210,547
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) Less than 1%
14	TYPE OF REPORTING PERSON PN

5

CUSIP NO. 129603106

1	NAME OF REPORTING PERSON STARBOARD VALUE R LP
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION DELAWARE
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 210,547
	8	SHARED VOTING POWER - 0 -
	9	SOLE DISPOSITIVE POWER 210,547
	10	SHARED DISPOSITIVE POWER - 0 -
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 210,547
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) Less than 1%
14	TYPE OF REPORTING PERSON PN

6

CUSIP NO. 129603106

1	NAME OF REPORTING PERSON STARBOARD VALUE R GP LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION DELAWARE
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 210,547
	8	SHARED VOTING POWER - 0 -
	9	SOLE DISPOSITIVE POWER 210,547
	10	SHARED DISPOSITIVE POWER - 0 -
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 210,547
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) Less than 1%
14	TYPE OF REPORTING PERSON OO

7

CUSIP NO. 129603106

1	NAME OF REPORTING PERSON STARBOARD VALUE GP LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION DELAWARE
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 3,245,000
	8	SHARED VOTING POWER - 0 -
	9	SOLE DISPOSITIVE POWER 3,245,000
	10	SHARED DISPOSITIVE POWER - 0 -
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,245,000
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 6.0%
14	TYPE OF REPORTING PERSON OO

8

CUSIP NO. 129603106

1	NAME OF REPORTING PERSON STARBOARD PRINCIPAL CO LP
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION DELAWARE
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 3,245,000
	8	SHARED VOTING POWER - 0 -
	9	SOLE DISPOSITIVE POWER 3,245,000
	10	SHARED DISPOSITIVE POWER - 0 -
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,245,000
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 6.0%
14	TYPE OF REPORTING PERSON PN

9

CUSIP NO. 129603106

1	NAME OF REPORTING PERSON STARBOARD PRINCIPAL CO GP LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION DELAWARE
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 3,245,000
	8	SHARED VOTING POWER - 0 -
	9	SOLE DISPOSITIVE POWER 3,245,000
	10	SHARED DISPOSITIVE POWER - 0 -
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,245,000
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 6.0%
14	TYPE OF REPORTING PERSON OO

10

CUSIP NO. 129603106

1	NAME OF REPORTING PERSON JEFFREY C. SMITH
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION USA
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER - 0 -
	8	SHARED VOTING POWER 3,245,000
	9	SOLE DISPOSITIVE POWER - 0 -
	10	SHARED DISPOSITIVE POWER 3,245,000
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,245,000
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 6.0%
14	TYPE OF REPORTING PERSON IN

11

CUSIP NO. 129603106

1	NAME OF REPORTING PERSON MARK R. MITCHELL
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION USA
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER - 0 -
	8	SHARED VOTING POWER 3,245,000
	9	SOLE DISPOSITIVE POWER - 0 -
	10	SHARED DISPOSITIVE POWER 3,245,000
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,245,000
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 6.0%
14	TYPE OF REPORTING PERSON IN

12

CUSIP NO. 129603106

1	NAME OF REPORTING PERSON PETER A. FELD
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION USA
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER - 0 -
	8	SHARED VOTING POWER 3,245,000
	9	SOLE DISPOSITIVE POWER - 0 -
	10	SHARED DISPOSITIVE POWER 3,245,000
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,245,000
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 6.0%
14	TYPE OF REPORTING PERSON IN

13

CUSIP NO. 129603106

The following constitutes Amendment No. 6 to the Schedule 13D filed by the undersigned (“Amendment No. 6”).  This Amendment No. 6 amends the Schedule 13D as specifically set forth herein.

Item 3. Source and Amount of Funds or Other Consideration.

Item 3 is hereby amended and restated as follows:

The Shares purchased by each of Starboard V&O Fund, Starboard S LLC and Starboard C LP and held in the Starboard Value LP Accounts were purchased with working capital (which may, at any given time, include margin loans made by brokerage firms in the ordinary course of business) in open market purchases, except as otherwise noted, as set forth in Schedule A, which is incorporated by reference herein.  The aggregate purchase price of the 1,811,556 Shares beneficially owned by Starboard V&O Fund is approximately $26,371,144, excluding brokerage commissions.  The aggregate purchase price of the 432,558 Shares beneficially owned by Starboard S LLC is approximately $7,257,387, excluding brokerage commissions. The aggregate purchase price of the 210,547 Shares beneficially owned by Starboard C LP is approximately $3,716,597, excluding brokerage commissions. The aggregate purchase price of the 790,339 Shares held in the Starboard Value LP Accounts is approximately $13,093,312, excluding brokerage commissions.

Item 5. Interest in Securities of the Issuer.

Items 5(a)-(c) are hereby amended and restated to read as follows:

The aggregate percentage of Shares reported owned by each person named herein is based upon 53,747,397 Shares outstanding, as of March 13, 2014, which is the total number of Shares outstanding as reported in the Issuer’s Definitive Proxy Statement filed with the Securities and Exchange Commission on March 25, 2014.

A. Starboard V&O Fund

(a) As of the close of business on May 5, 2014, Starboard V&O Fund beneficially owned 1,811,556 Shares.

Percentage: Approximately 3.4%

(b) 1. Sole power to vote or direct vote: 1,811,556

2. Shared power to vote or direct vote: 0

3. Sole power to dispose or direct the disposition: 1,811,556

4. Shared power to dispose or direct the disposition: 0

(c) The transactions in the Shares by Starboard V&O Fund during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

B. Starboard S LLC

(a) As of the close of business on May 5, 2014, Starboard S LLC beneficially owned 432,558 Shares.

Percentage: Less than 1%

14

CUSIP NO. 129603106

(b) 1. Sole power to vote or direct vote: 432,558

2. Shared power to vote or direct vote: 0

3. Sole power to dispose or direct the disposition: 432,558

4. Shared power to dispose or direct the disposition: 0

(c) The transactions in the Shares by Starboard S LLC during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

C. Starboard C LP

(a) As of the close of business on May 5, 2014, Starboard C LP beneficially owned 210,547 Shares.

Percentage: Less than 1%

(b) 1. Sole power to vote or direct vote: 210,547

2. Shared power to vote or direct vote: 0

3. Sole power to dispose or direct the disposition: 210,547

4. Shared power to dispose or direct the disposition: 0

(c) The transactions in the Shares by Starboard C LP during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

D. Starboard R LP

(a) Starboard R LP, as the general partner of Starboard C LP, may be deemed the beneficial owner of the 210,547 shares owned by Starboard C LP.

Percentage: Less than 1%

(b) 1. Sole power to vote or direct vote: 210,547

2. Shared power to vote or direct vote: 0

3. Sole power to dispose or direct the disposition: 210,547

4. Shared power to dispose or direct the disposition: 0

(c) Starboard R LP has not entered into any transactions in the Shares during the past sixty days.  The transactions in the Shares on behalf of Starboard C LP during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

E. Starboard R GP

(a) Starboard R GP, as the general partner of Starboard R LP, may be deemed the beneficial owner of the 210,547 shares owned by Starboard C LP.

Percentage: Less than 1%

(b) 1. Sole power to vote or direct vote: 210,547

2. Shared power to vote or direct vote: 0

3. Sole power to dispose or direct the disposition: 210,547

4. Shared power to dispose or direct the disposition: 0

15

CUSIP NO. 129603106

(c) Starboard R GP has not entered into any transactions in the Shares during the past sixty days.  The transactions in the Shares on behalf of Starboard C LP during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

F. Starboard Value LP

(a) As of the close of business on May 5, 2014, 790,339 Shares were held in the Starboard Value LP Accounts.  Starboard Value LP, as the investment manager of Starboard V&O Fund, Starboard C LP and the Starboard Value LP Accounts, and the manager of Starboard S LLC, may be deemed the beneficial owner of the (i) 1,811,556 Shares owned by Starboard V&O Fund, (ii) 432,558 Shares owned by Starboard S LLC, (iii) 210,547 Shares owned by Starboard C LP and (iv) 790,339 Shares held in the Starboard Value LP Accounts.

Percentage: Approximately 6.0%

(b) 1. Sole power to vote or direct vote: 3,245,000

2. Shared power to vote or direct vote: 0

3. Sole power to dispose or direct the disposition: 3,245,000

4. Shared power to dispose or direct the disposition: 0

(c) The transactions in the Shares by Starboard Value LP through the Starboard Value LP Accounts and on behalf of each of Starboard V&O Fund, Starboard S LLC and Starboard C LP during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

G. Starboard Value GP

(a) Starboard Value GP, as the general partner of Starboard Value LP, may be deemed the beneficial owner of the (i) 1,811,556 Shares owned by Starboard V&O Fund, (ii) 432,558 Shares owned by Starboard S LLC, (iii) 210,547 Shares owned by Starboard C LP and (iv) 790,339 Shares held in the Starboard Value LP Accounts.

Percentage: Approximately 6.0%

(b) 1. Sole power to vote or direct vote: 3,245,000

2. Shared power to vote or direct vote: 0

3. Sole power to dispose or direct the disposition: 3,245,000

4. Shared power to dispose or direct the disposition: 0

(c) Starboard Value GP has not entered into any transactions in the Shares during the past sixty days.  The transactions in the Shares on behalf of each of Starboard V&O Fund, Starboard S LLC, Starboard C LP and through the Starboard Value LP Accounts during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

H. Principal Co

(a) Principal Co, as a member of Starboard Value GP, may be deemed the beneficial owner of the (i) 1,811,556 Shares owned by Starboard V&O Fund, (ii) 432,558 Shares owned by Starboard S LLC, (iii) 210,547 Shares owned by Starboard C LP and (iv) 790,339 Shares held in the Starboard Value LP Accounts.

Percentage: Approximately 6.0%

16

CUSIP NO. 129603106

(b) 1. Sole power to vote or direct vote: 3,245,000

2. Shared power to vote or direct vote: 0

3. Sole power to dispose or direct the disposition: 3,245,000

4. Shared power to dispose or direct the disposition: 0

(c) Principal Co has not entered into any transactions in the Shares during the past sixty days.  The transactions in the Shares on behalf of each of Starboard V&O Fund, Starboard S LLC, Starboard C LP and through the Starboard Value LP Accounts during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

I. Principal GP

(a) Principal GP, as the general partner of Principal Co, may be deemed the beneficial owner of the (i) 1,811,556 Shares owned by Starboard V&O Fund, (ii) 432,558 Shares owned by Starboard S LLC, (iii) 210,547 Shares owned by Starboard C LP and (iv) 790,339 Shares held in the Starboard Value LP Accounts.

Percentage: Approximately 6.0%

(b) 1. Sole power to vote or direct vote: 3,245,000

2. Shared power to vote or direct vote: 0

3. Sole power to dispose or direct the disposition: 3,245,000

4. Shared power to dispose or direct the disposition: 0

(c) Principal GP has not entered into any transactions in the Shares during the past sixty days.  The transactions in the Shares on behalf of each of Starboard V&O Fund, Starboard S LLC, Starboard C LP and through the Starboard Value LP Accounts during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

J. Messrs. Smith, Mitchell and Feld

(a) Each of Messrs. Smith, Mitchell and Feld, as a member of Principal GP and as a member of each of the Management Committee of Starboard Value GP and the Management Committee of Principal GP, may be deemed the beneficial owner of the (i) 1,811,556 Shares owned by Starboard V&O Fund, (ii) 432,558 Shares owned by Starboard S LLC, (iii) 210,547 Shares owned by Starboard C LP and (iv) 790,339 Shares held in the Starboard Value LP Accounts.

Percentage: Approximately 6.0%

(b) 1. Sole power to vote or direct vote: 0

2. Shared power to vote or direct vote: 3,245,000

3. Sole power to dispose or direct the disposition: 0

4. Shared power to dispose or direct the disposition: 3,245,000

(c) None of Messrs. Smith, Mitchell or Feld has entered into any transactions in the Shares during the past sixty days.  The transactions in the Shares on behalf of each of Starboard V&O Fund, Starboard S LLC, Starboard C LP and through the Starboard Value LP Accounts during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

Each Reporting Person, as a member of a “group” with the other Reporting Persons for the purposes of Section 13(d)(3) of the Securities Exchange Act of 1934, as amended, may be deemed the beneficial owner of the Shares directly owned by the other Reporting Persons.  Each Reporting Person disclaims beneficial ownership of such Shares except to the extent of his or its pecuniary interest therein.

17

CUSIP NO. 129603106

SIGNATURES

After reasonable inquiry and to the best of his knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.

Dated:  May 6, 2014

STARBOARD VALUE AND OPPORTUNITY MASTER FUND LTD By: Starboard Value LP,        its investment manager   STARBOARD VALUE AND OPPORTUNITY S LLC By: Starboard Value LP,        its manager   STARBOARD VALUE AND OPPORTUNITY C LP By: Starboard Value R LP        its general partner   STARBOARD VALUE R LP By: Starboard Value R GP LLC,        its general partner   STARBOARD VALUE LP By: Starboard Value GP LLC,        its general partner STARBOARD VALUE GP LLC By: Starboard Principal Co LP,        its member   STARBOARD PRINCIPAL CO LP By: Starboard Principal Co GP LLC,        its general partner   STARBOARD PRINCIPAL CO GP LLC   STARBOARD VALUE R GP LLC

By:	/s/ Jeffrey C. Smith
	Name:	Jeffrey C. Smith
	Title:	Authorized Signatory

/s/ Jeffrey C. Smith

JEFFREY C. SMITH

Individually and as attorney-in-fact for Mark R. Mitchell and Peter A. Feld

18

CUSIP NO. 129603106

SCHEDULE A

Transactions in the Shares During the Past Sixty Days

Shares of Common Stock Purchased/(Sold) Price Per Share($) Date of Purchase/Sale

STARBOARD VALUE AND OPPORTUNITY MASTER FUND LTD

10,601	20.6057	03/14/2014
9,517	20.5717	03/17/2014
17,578	20.6868	03/18/2014
33,374	20.6352	03/19/2014
28,428	20.6423	03/20/2014
(5,580)	21.8964	04/02/2014
(5,580)	21.8151	04/03/2014
(11,160)	21.3856	04/08/2014
(47,432)	21.1094	04/09/2014
(41,852)	20.4426	04/10/2014
(11,160)	20.2388	04/11/2014
(14,955)	20.3953	04/16/2014
(1,786)	20.5472	04/16/2014
(8,370)	20.6085	04/17/2014
(5,580)	20.5678	04/17/2014
19,012	20.2201	04/29/2014
9,705	20.0782	04/30/2014
(19,540)	19.8823	05/01/2014
(23,335)	20.1779	05/02/2014
(43,656)	19.8401	05/05/2014

STARBOARD VALUE AND OPPORTUNITY S LLC

2,470	20.6057	03/14/2014
2,217	20.5717	03/17/2014
4,095	20.6868	03/18/2014
7,776	20.6352	03/19/2014
6,624	20.6423	03/20/2014
(1,333)	21.8964	04/02/2014
(1,333)	21.8151	04/03/2014
(2,666)	21.3856	04/08/2014
(11,333)	21.1094	04/09/2014
(9,999)	20.4426	04/10/2014
(2,666)	20.2388	04/11/2014
(3,573)	20.3953	04/16/2014
(427)	20.5472	04/16/2014
(2,000)	20.6085	04/17/2014
(1,333)	20.5678	04/17/2014
4,353	20.2201	04/29/2014
2,222	20.0782	04/30/2014
(4,665)	19.8823	05/01/2014
(5,572)	20.1779	05/02/2014
(10,424)	19.8401	05/05/2014

CUSIP NO. 129603106

STARBOARD VALUE AND OPPORTUNITY C LP

1,370	20.6057	03/14/2014
1,230	20.5717	03/17/2014
2,272	20.6868	03/18/2014
4,314	20.6352	03/19/2014
3,674	20.6423	03/20/2014
(648)	21.8964	04/02/2014
(648)	21.8151	04/03/2014
(1,296)	21.3856	04/08/2014
(5,505)	21.1094	04/09/2014
(4,858)	20.4426	04/10/2014
(1,296)	20.2388	04/11/2014
(1,736)	20.3953	04/16/2014
(206)	20.5472	04/16/2014
(972)	20.6085	04/17/2014
(648)	20.5678	04/17/2014
2,401	20.2201	04/29/2014
1,226	20.0782	04/30/2014
(2,271)	19.8823	05/01/2014
(2,712)	20.1779	05/02/2014
(5,073)	19.8401	05/05/2014

STARBOARD VALUE LP

(Through the Starboard Value LP Accounts)

4,205	20.6057	03/14/2014
3,774	20.5717	03/17/2014
6,971	20.6868	03/18/2014
13,236	20.6352	03/19/2014
11,274	20.6423	03/20/2014
(2,439)	21.8964	04/02/2014
(2,439)	21.8151	04/03/2014
(4,878)	21.3856	04/08/2014
(20,730)	21.1094	04/09/2014
(18,291)	20.4426	04/10/2014
(4,878)	20.2388	04/11/2014
(6,536)	20.3953	04/16/2014
(781)	20.5472	04/16/2014
(2,439)	20.5678	04/17/2014
(3,658)	20.6085	04/17/2014
7,336	20.2201	04/29/2014
3,745	20.0782	04/30/2014
(8,524)	19.8823	05/01/2014
(10,181)	20.1779	05/02/2014
(19,047)	19.8401	05/05/2014