My computation has an  intermediate variable-length list of 3-D PyTorch Variables of different sizes (say [32x32x3, 16x2x36, 18x6x12]).   What would be the easiest way to add up all the Variables after the necessary padding? For the example I’ve given, the final output would have size 32x32x36. Note that this addition needs to be done in a way that gradients can flow backwards.