Exhibit 24 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation of our report dated March 21, 1997, included in this Form 10-K, into the Company's previously filed Amendment No. 3 to Form S-4 Registration Statement No. 33-21412, Amendment No. 1 to Form S-8 Registration Statement No. 33-24927 and Amendment No. 4 to Form S-1 Registration Statement. ARTHUR ANDERSEN LLP Washington, D.C., March 31, 1997