You are given a 2D matrix grid of size m x n. In one operation, you can change the value of any cell to any non-negative number. You need to perform some operations such that each cell grid[i][j] is:

Equal to the cell below it, i.e. grid[i][j] == grid[i + 1][j] (if it exists).
Different from the cell to its right, i.e. grid[i][j] != grid[i][j + 1] (if it exists).

Return the minimum number of operations needed.

Example 1:

Input: grid = [[1,0,2],[1,0,2]]

Output: 0

Explanation:

All the cells in the matrix already satisfy the properties.

Example 2:

Input: grid = [[1,1,1],[0,0,0]]

Output: 3

Explanation:

The matrix becomes [[1,0,1],[1,0,1]] which satisfies the properties, by doing these 3 operations:

Change grid[1][0] to 1.
Change grid[0][1] to 0.
Change grid[1][2] to 1.

Example 3:

Input: grid = [[1],[2],[3]]

Output: 2

Explanation:

There is a single column. We can change the value to 1 in each cell using 2 operations.

Constraints:

1 <= n, m <= 1000
0 <= grid[i][j] <= 9