POWER OF ATTORNEY

        Know all by these presents, that the undersigned hereby constitutes and
appoints Heath Weisberg, signing singly,with full power of substitution, the
undersigned's true and lawful attorney-in-fact to:

        (1) execute for and on behalf of the undersigned any applications,
reports, or documents required or deemed appropriate by the attorney-in-fact to
file pursuant to (i) the United States Securities Exchange Act of 1934, as
amended, or any rule, or regulation thereunder, including, without limitation,
Schedules 13D, 13G, 13F, and 13H, andForms 3, 4, and 5, (ii) the Securities Act
of 1933, as amended, or any rule or regulation thereunder, including, without
limitation, Form 144, (iii) the U.S. Commodity Exchange Act, as amended or any
rule or regulation thereunder, or (iv) the statutes, rules or regulations of any
other domestic or foreign governmental or self-regulatory authority;

        (2) do and perform any and all acts for and on behalf of the undersigned
which may be necessary or desirable to complete and execute any such
applications, reports, or documents;

        (3) take any other action of any type whatsoever in connection with the
foregoing which, in the opinion of such attorney-in-fact, may be of benefit to,
in the best interests of, or legally required by the undersigned, it being
understood that the documents executed by such attorney-in-fact on behalf of the
undersigned pursuant to this Power of Attorney shall be in such form and shall
contain such terms and conditions as such attorney-in-fact may approve in such
attorney-in-fact's discretion.

        The undersigned hereby grants to each such attorney-in-fact full power
and authority to do and perform any and every act and thing whatsoever
requisite, necessary, or proper to be done in the exercise of any of the rights
and powers herein granted, as fully to all intents and purposes as the
undersigned might or could do if personally present,with full power of
substitution or revocation, hereby ratifying and confirming all that such
attorney-in-fact, or such attorney-in-fact's substitute or substitutes, shall
lawfully do or cause to be done by virtue of this power of attorney
and the rights and powers herein granted. The undersigned acknowledges that the
foregoing attorney-in-fact, in serving in such capacity at the request of the
undersigned, are not assuming, nor is the Company assuming, any of the
undersigned's responsibilities to comply with the applicable statutes, rules and
regulations.

        This Power of Attorney shall remain in full force and effect until
revoked by the undersigned in a signed writing delivered to the foregoing
attorney-in-fact or otherwise terminated by my death or other event described in
section 5-1511 of the New York General Obligations Law.

SIGNATURE AND ACKNOWLEDGMENT:

        In Witness Whereof I have hereunto signed my name on the 9th day of May,
 2013.

        /s/ Bruce Kovner
        ----------------------
        Bruce Kovner


STATE OF NEW YORK    )
                     )  ss:
COUNTY OF NEW YORK   )

        On the 9th day of May 2013, before me, the undersigned, personally
appeared Bruce Kovner, personally known to me or proved to me on the basis of
satisfactory evidence to be the individual whose name is subscribed to the
within instrument and acknowledged to me that he/she executed the same in
his/her capacity, and that by his/her signature on the instrument, the
individual, or the person upon behalf of which the individual acted, executed
the instrument.

        /s/ Cynthia Rosel Rivera
        ------------------------
        Notary Public

AGENT'S SIGNATURE AND ACKNOWLEDGMENT OF APPOINTMENT:

        I, Heath N. Weisberg, have read the foregoing Power of Attorney. I am
the person identified therein as agent and attorney-in-fact for the principal
named therein.

        I acknowledge my legal responsibilities.

        /s/ Heath N. Weisberg
        ------------------------
        Heath N. Weisberg


STATE OF NEW YORK    )
                     ) ss:
COUNTY OF NEW YORK   )

        On the 9th day of May, 2013, before me, the undersigned, personally
appeared Heath N. Weisberg, personally known to me or proved to me on the basis
of satisfactory evidence to be the individual whose name is subscribed to the
within instrument and acknowledged to me that he/she executed the same in
his/her capacity, and that by his/her signature on the instrument, the
individual, or the person upon behalf of which the individual acted, executed
the instrument.

        /s/ Cynthia Rosel Rivera
        ------------------------
        Notary Public