I have a matrix A which is 3d and I want to convert so that it is equal to B which is a 2d matrix
> A = torch.tensor( [ [[1,1,1,1,1],
>          [2,2,2,2,2],
>          [3,3,3,3,3],
>          [4,4,4,4,4],
>          [ 5,5,5,5,5]],
> 
>         [[6,6,6,6,6]
>          [7,7,7,7,7],
>          [8,8,8,8,8],
>          [9,9,9,9,9],
>          [ 10,10,10,10,10]],
> 
>         [[11,11,11,11,11],
>          [12,12,12,12,12],
>          [13,13,13,13,13],
>          [14,14,14,14,14],
>          [ 15,15,15,15,15]]])
> 
> B = torch.tensor( [[1,1,1,1,1, 6,6,6,6,6, 11,11,11,11,11],
>          [2,2,2,2,2, 7,7,7,7,7, 12,12,12,12,12],
>          [3,3,3,3,3, 8,8,8,8,8, 13,13,13,13,13],
>          [4,4,4,4,4, 9,9,9,9,9, 14,14,14,14,14],
>          [ 5,5,5,5,5, 10,10,10,10,10, 15,15,15,15,15]])

Please help