CUSIP No. 34385P108 Page 9 of 9

Exhibit A

JOINT FILING AGREEMENT

Pursuant to Rule 13d-1(k)(1) of the Securities and Exchange Commission under the Securities Exchange Act of 1934, as amended, each of the undersigned agrees that the statement on Schedule 13G filed herewith shall be filed on behalf of each of the undersigned and further agrees that this joint filing agreement be included as an exhibit to this Schedule 13G.  In evidence thereof, the undersigned hereby execute this Agreement as of September 11, 2015.

MUBADALA DEVELOPMENT COMPANY PJSC

By:  Samer Halawa

Attorney-in-fact

/s/ Samer Halawa

Signature

Samer Halawa / Attorney-in-fact

MDC CAPITAL LLC

By:  Rodney Cannon

Director

/s/ Rodney Cannon

Signature

Rodney Cannon / Director

Name/Title

By:  Hani Barhoush

Director

/s/ Hani Barhoush

Signature

Hani Barhoush / Director

Name/Title

MDC CAPITAL (CAYMAN) LIMITED, AS TRUSTEE FOR FIFTY FIRST INVESTMENT COMPANY LLC

By:  Rodney Cannon

Director

/s/ Rodney Cannon

Signature

Rodney Cannon / Director

Name/Title

By:  Hani Barhoush

Director

/s/ Hani Barhoush

Signature

Hani Barhoush / Director

Name/Title