040000 tree 5cd5462994ef52a634c01c40e97f2dfb253f6aaf	build
040000 tree 9168fd933736d1efc540c6bc9daa82b9f49ef617	it
040000 tree c061e3d04055d5b0da73c795ed1cce3c029dd632	main
040000 tree 1758b2aad9077f7103fde534ef68e8f5cf368806	test