||If the form is filed by more than one reporting person, see Instruction 5(b)(v).
||Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
||This is a joint filing by Austin W. Marxe (Marxe), David M. Greenhouse (Greenhouse) and Adam C. Stettner (Stettner). Special Situations Fund III QP, L.P. (SSFQP), Special Situations Cayman Fund, L.P. (CAYMAN) and Special Situations Private Equity Fund, L.P. (SSPE and together with SSFQP and CAYMAN, the Funds) hold shares of Common Stock of the Issuer (the Shares). AWM Investment Company, Inc. (AWM), the investment adviser to the Funds, holds the power to vote and the power to dispose of the Shares held by each of the Funds. Marxe, Greenhouse and Stettner are the controlling principals of AWM.
||While the Shares held by each of the Funds were previously reported by Marxe, Greenhouse and Stettner on Form 3, reference should be made to AWM (CIK #0001002856) for any future filings with the Securities and Exchange Commission relating to the Shares held by each of the Funds. Marxe, Greenhouse and Stettner disclaim beneficial ownership of the Shares, except to the extent of their pecuniary interest therein. This report shall not be deemed an admission that Marxe, Greenhouse and Stettner are the beneficial owners of the Shares of the Issuer held by the Funds for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.