<p>Given a rectangular pizza represented as a <code>rows x cols</code> matrix containing the following characters: <code>'A'</code> (an apple) and <code>'.'</code> (empty cell) and given the integer <code>k</code>. You have to cut the pizza into <code>k</code> pieces using <code>k-1</code> cuts. </p>
<p>For each cut you choose the direction: vertical or horizontal, then you choose a cut position at the cell boundary and cut the pizza into two pieces. If you cut the pizza vertically, give the left part of the pizza to a person. If you cut the pizza horizontally, give the upper part of the pizza to a person. Give the last piece of pizza to the last person.</p>
<p><em>Return the number of ways of cutting the pizza such that each piece contains <strong>at least</strong> one apple. </em>Since the answer can be a huge number, return this modulo 10^9 + 7.</p>
