Update README.md

README.md

@@ -52,7 +52,7 @@ from torch_scatter import scatter_max
 src = torch.tensor([[2, 0, 1, 4, 3], [0, 2, 1, 3, 4]])
 index = torch.tensor([[4, 5, 4, 2, 3], [0, 0, 2, 2, 1]])
 
-out, argmax = scatter_max(src, input)
+out, argmax = scatter_max(src, index)
 ```
 
 ```