Sasha and Photos

Sasha is a little girl who likes to view and compare photos. In this problem, a photo is a grid of pixels with $h$ rows and $w$ columns; each cell of this grid is either black or white. We will call the ordered pair of integers $(h, w)$ the *shape* of a photo. Let's define the *similarity* of two photos $P$ and $R$ with **the same** shape $(h, w)$ as the number of pairs of indices $i, j$ ($1 \le