You are given an m x n grid where each cell can have one of three values:

• 0 representing an empty cell
• 1 representing a fresh orange
• 2 representing a rotten orange

Every minute, any fresh orange that is 4-directionally adjacent to a rotten orange becomes rotten.

Return the minimum number of minutes that must elapse until no cell has a fresh orange. If this is impossible, return -1.

Example 1:

Input:
3 3
2 1 1
1 1 0
0 1 1
Output: 4

Example 2:

Input:
3 3
2 1 1
0 1 1
1 0 1
Output: -1

Constraints:

• m == grid.length, n == grid[i].length
• 1 ≤ m, n ≤ 10
• grid[i][j] is 0, 1, or 2

Input format: First line: m n. Then m lines each with n space-separated integers (0, 1, or 2).

Output format: Minimum minutes or -1.