Hi,

I am not sure how is that the correct answer. Don’t we have to solve for P?

Hi @Moutasem_Akkad,

Thanks for pointing this out. The explanation given after grading is not matching the problem (where does the 121 come from?), and we do need to solve for `p`

as you ask, using the formula `n_H = (n_H + 2p -f )/s + 1`

.

We want to keep the `n_H`

of 64 after the convolution. Therefore, we can solve for `p`

as follows, with `n_H=64, f=9, s=1`

:

`64 = (64+2p-9)/1 + 1`

`0 = 2p-8`

`p = 4`

So the padding size of 4 is correct.

It turns out that, as long as the stride `s`

is 1, the value of `n_H`

(be it 64 or 121) does not matter in solving for `p`

, as it gets cancelled out anyway.

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Thanks, one more suggestion. I have noticed that some of the notes (corrections) about certain lectures come after the lecture. Might be helpful to have them before the lectures.