The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE

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COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
ALPHABET INC CAP STK CL A 02079K305 37,776 21,554 SH   SOLE   21,554 0 0
ALPHABET INC CAP STK CL C 02079K107 37,650 21,491 SH   SOLE   21,491 0 0
AMAZON COM INC COM 023135106 98,457 30,230 SH   SOLE   30,230 0 0
APPLE INC COM 037833100 132,967 1,002,088 SH   SOLE   1,002,088 0 0
BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 9,762,747 42,104,399 SH   SOLE   42,104,399 0 0
CANADIAN NATL RY CO COM 136375102 1,865,173 16,979,268 SH   SOLE   16,979,268 0 0
CATERPILLAR INC COM 149123101 2,049,701 11,260,857 SH   SOLE   11,260,857 0 0
COCA-COLA FEMSA SAB DE CV SPONSORD ADR REP 191241108 286,499 6,214,719 SH   SOLE   6,214,719 0 0
CROWN CASTLE INTL CORP NEW COM 22822V101 848,944 5,332,900 SH   SOLE   5,332,900 0 0
ECOLAB INC COM 278865100 944,720 4,366,426 SH   SOLE   4,366,426 0 0
FEDEX CORP COM 31428X106 785,350 3,024,999 SH   SOLE   3,024,999 0 0
GRUPO TELEVISA SA SPON ADR REP ORD 40049J206 139,084 16,879,104 SH   SOLE   16,879,104 0 0
LIBERTY GLOBAL PLC SHS CL A G5480U104 51,335 2,119,515 SH   SOLE   2,119,515 0 0
LIBERTY GLOBAL PLC SHS CL C G5480U120 86,071 3,639,349 SH   SOLE   3,639,349 0 0
LIBERTY LATIN AMERICA LTD COM CL A G9001E102 3,077 276,443 SH   SOLE   276,443 0 0
LIBERTY LATIN AMERICA LTD COM CL C G9001E128 7,508 676,979 SH   SOLE   676,979 0 0
SCHRODINGER INC COM 80810D103 552,808 6,981,664 SH   SOLE   6,981,664 0 0
TWITTER INC COM 90184L102 14,752 272,420 SH   SOLE   272,420 0 0
UNITED PARCEL SERVICE INC CL B 911312106 762,065 4,525,329 SH   SOLE   4,525,329 0 0
WALMART INC COM 931142103 1,672,572 11,603,000 SH   SOLE   11,603,000 0 0
WASTE MGMT INC DEL COM 94106L109 2,197,469 18,633,672 SH   SOLE   18,633,672 0 0