<p>You are given a <strong>0-indexed</strong> 2D integer matrix <code>grid</code> of size <code>3 * 3</code>, representing the number of stones in each cell. The grid contains exactly <code>9</code> stones, and there can be <strong>multiple</strong> stones in a single cell.</p> <p>In one move, you can move a single stone from its current cell to any other cell if the two cells share a side.</p> <p>Return <em>the <strong>minimum number of moves</strong> required to place one stone in each cell</em>.</p> <p> </p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://assets.leetcode.com/uploads/2023/08/23/example1-3.svg" style="width: 401px; height: 281px;" /> <pre> <strong>Input:</strong> grid = [[1,1,0],[1,1,1],[1,2,1]] <strong>Output:</strong> 3 <strong>Explanation:</strong> One possible sequence of moves to place one stone in each cell is: 1- Move one stone from cell (2,1) to cell (2,2). 2- Move one stone from cell (2,2) to cell (1,2). 3- Move one stone from cell (1,2) to cell (0,2). In total, it takes 3 moves to place one stone in each cell of the grid. It can be shown that 3 is the minimum number of moves required to place one stone in each cell. </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://assets.leetcode.com/uploads/2023/08/23/example2-2.svg" style="width: 401px; height: 281px;" /> <pre> <strong>Input:</strong> grid = [[1,3,0],[1,0,0],[1,0,3]] <strong>Output:</strong> 4 <strong>Explanation:</strong> One possible sequence of moves to place one stone in each cell is: 1- Move one stone from cell (0,1) to cell (0,2). 2- Move one stone from cell (0,1) to cell (1,1). 3- Move one stone from cell (2,2) to cell (1,2). 4- Move one stone from cell (2,2) to cell (2,1). In total, it takes 4 moves to place one stone in each cell of the grid. It can be shown that 4 is the minimum number of moves required to place one stone in each cell. </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>grid.length == grid[i].length == 3</code></li> <li><code>0 <= grid[i][j] <= 9</code></li> <li>Sum of <code>grid</code> is equal to <code>9</code>.</li> </ul>