<p>You are given an <code>m x n</code> matrix <code>M</code> initialized with all <code>0</code>'s and an array of operations <code>ops</code>, where <code>ops[i] = [a<sub>i</sub>, b<sub>i</sub>]</code> means <code>M[x][y]</code> should be incremented by one for all <code>0 <= x < a<sub>i</sub></code> and <code>0 <= y < b<sub>i</sub></code>.</p> <p>Count and return <em>the number of maximum integers in the matrix after performing all the operations</em>.</p> <p> </p> <p><strong>Example 1:</strong></p> <img alt="" src="https://assets.leetcode.com/uploads/2020/10/02/ex1.jpg" style="width: 750px; height: 176px;" /> <pre> <strong>Input:</strong> m = 3, n = 3, ops = [[2,2],[3,3]] <strong>Output:</strong> 4 <strong>Explanation:</strong> The maximum integer in M is 2, and there are four of it in M. So return 4. </pre> <p><strong>Example 2:</strong></p> <pre> <strong>Input:</strong> m = 3, n = 3, ops = [[2,2],[3,3],[3,3],[3,3],[2,2],[3,3],[3,3],[3,3],[2,2],[3,3],[3,3],[3,3]] <strong>Output:</strong> 4 </pre> <p><strong>Example 3:</strong></p> <pre> <strong>Input:</strong> m = 3, n = 3, ops = [] <strong>Output:</strong> 9 </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= m, n <= 4 * 10<sup>4</sup></code></li> <li><code>0 <= ops.length <= 10<sup>4</sup></code></li> <li><code>ops[i].length == 2</code></li> <li><code>1 <= a<sub>i</sub> <= m</code></li> <li><code>1 <= b<sub>i</sub> <= n</code></li> </ul>