fix index format (#3343) #4257

Job	Run time
pytorch_tutorial_build_worker (1, 15, linux.g5.12xlarge.nvidia.gpu)	16m 4s
pytorch_tutorial_build_worker (2, 15, linux.g5.4xlarge.nvidia.gpu)	33m 51s
pytorch_tutorial_build_worker (10, 15, linux.g5.4xlarge.nvidia.gpu)	17m 40s
pytorch_tutorial_build_worker (13, 15, linux.g5.4xlarge.nvidia.gpu)	29m 13s
pytorch_tutorial_build_worker (8, 15, linux.g5.4xlarge.nvidia.gpu)	15m 55s
pytorch_tutorial_build_worker (5, 15, linux.g5.4xlarge.nvidia.gpu)	25m 23s
pytorch_tutorial_build_worker (11, 15, linux.g5.4xlarge.nvidia.gpu)	14m 26s
pytorch_tutorial_build_worker (3, 15, linux.g5.4xlarge.nvidia.gpu)	22m 56s
pytorch_tutorial_build_worker (4, 15, linux.g5.4xlarge.nvidia.gpu)	35m 45s
pytorch_tutorial_build_worker (9, 15, linux.g5.4xlarge.nvidia.gpu)	18m 42s
pytorch_tutorial_build_worker (12, 15, linux.g5.4xlarge.nvidia.gpu)	20m 34s
pytorch_tutorial_build_worker (14, 15, linux.g5.4xlarge.nvidia.gpu)	25m 3s
pytorch_tutorial_build_worker (6, 15, linux.g5.4xlarge.nvidia.gpu)	23m 20s
pytorch_tutorial_build_worker (7, 15, linux.g5.4xlarge.nvidia.gpu)	25m 47s
pytorch_tutorial_build_worker (15, 15, linux.g5.4xlarge.nvidia.gpu)	28m 11s
pytorch_tutorial_build_manager	26m 22s
	6h 19m 12s

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