| Explanation of Responses: |
| (1) | These securities are owned directly by Warren E. Buffett, who is a reporting person hereunder. |
| (2) | 149,497,786 of the total reported securities are owned directly by the following subsidiaries of Berkshire Hathaway Inc. ("Berkshire"): AmGUARD Insurance Company (500,000), Berkshire Hathaway Assurance Corporation (4,173,800), Berkshire Hathaway Direct Insurance Company (29,000), Berkshire Hathaway Homestate Insurance Company (3,850,000), Berkshire Hathaway Life Insurance Company of Nebraska (3,912,000), Berkshire Hathaway Specialty Insurance Company (9,151,626), BHG Life Insurance Company (928,500), British Insurance Company of Cayman (476,000), Columbia Insurance Company (23,307,300), Cypress Insurance Company (1,175,000), EastGUARD Insurance Company (200,000), Government Employees Insurance Company (8,191,300), GEICO Indemnity Company (4,488,000), General Re Life Corporation (1,427,343), General Reinsurance Corporation (14,559,100), General Star Indemnity Company (1,400,000), General Star National Insurance Company (136,000), |
| (3) | Continued from Footnote 2: Genesis Insurance Company (106,000), The Medical Protective Company (4,204,800), MPP Company, Inc. (388,000), Mount Vernon Fire Insurance Company (585,000), National Fire & Marine Insurance Company (3,789,000), National Indemnity Company (55,796,117), National Indemnity Company of Mid America (474,300), National Indemnity Company of the South (297,600), NorGUARD Insurance Company (767,000), NRG America Holding Company (495,000), Old United Casualty Company (259,000), Redwood Fire and Casualty Insurance Company (3,050,000), United States Liability Insurance Company (985,000), U.S. Underwriters Insurance Company (175,000) and WestGUARD Insurance Company (221,000). In order to avoid double counting, shares of Common Stock reported as being owned by each of these subsidiaries only reflect shares that are owned directly by such subsidiary, |
| (4) | Continued from footnote 3: and do not reflect any shares that such subsidiary may be deemed to beneficially own by virtue of ownership or control of any other subsidiary otherwise reported in this Form 3. As Berkshire is in the chain of ownership of each subsidiary listed above, it may be deemed presently to both beneficially own and have a pecuniary interest in all shares of Common Stock presently directly owned by such subsidiaries. Warren E. Buffett, as the controlling stockholder of Berkshire, may be deemed presently to beneficially own, but only to the extent he has a pecuniary interest in, the shares of Common Stock presently owned by each of these subsidiaries. Mr. Buffett disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interest therein. |
| (5) | 590,275 of the total reported securities are owned directly by the Benjamin Moore Pension Trust, a pension plan of a Berkshire subsidiary. Each of Berkshire, Mr. Buffett and this pension plan disclaim beneficial ownership in such shares. |