CONFIDENTIAL DRAFT FOR PURPOSES OF SETTLEMENT DISCUSSIONS ONLY August 26, 2013 William H. Gates RE: Letter of Agreement Regarding Purchase of Interest in Investment Entity Dear Bill: This letter sets forth the agreement by and between you, William H. Gates ("Mr. Gates"), and me, Dr. Boris Nikolic ("Dr. Nikolic"), with respect to the purchase by Mr. Gates from Dr. Nikolic of Dr. Nikotic's interest created under our prior agreement in a certain $30 Million to $50 Million Investment Entity (the "Investment Entity"). With respect to Mr. Gates's purchase from Dr. Nikolic of Dr. Nikolic's interest in the Investment Entity, Mr. Gates and Dr. Nikolic have agreed as follows: Termination of On February 15, 2014, Dr. Nikolic's employment with bgC3 LLC shall Employment and terminate, as will all financial and business relationships between Dr. Business and Nikolic, on the one hand, and each of Mr. Gates, Melinda F. Gates, the Bill Financial and Melinda Gates Foundation and all other entities owned or controlled Relationships by William H. Gates, on the other hand, except for those relationships created by the provisions of this Agreement. Sale and Purchase Dr. Nikolic shall sell, transfer and convey to Mr. Gates, and Mr. Gates of Interest in shall purchase from Dr. Nikolic, all of Dr. Nikolic's right, title and interest Investment Entity in and to the Investment Entity for a purchase price equal to the aggregate of all Investment Entity Payment Demands (as hereinafter defined) made by Dr. Nikolic to Mr. Gates during the Payment Period (as hereinafter defined). Such sale and purchase shall be deemed to have been completed, effective upon Mr. Gates's payment in full to Dr. Nikolic of all Investment Entity Payment Demands, together will all other amounts due and payable by Mr. Gates to Dr. Nikolic, under this Agreement. Advance SE-251912 vl Simultaneously with the execution of this Agreement by the parties hereto, Mr. Gates will pay Dr. Niko