Rotten Oranges

class Solution:
    def orangesRotting(self, grid: List[List[int]]) -> int:

        q = deque()
        n, m = len(grid), len(grid[0])
        fresh = 0
        rotten = 0
        level = 0

        for i in range(n):
            for j in range(m):
                if grid[i][j] == 2:
                    q.append((i, j))
                if grid[i][j] == 1:
                    fresh += 1

        while q:
            for _ in range(len(q)):
                (r, c) = q.popleft()

                directions = [(1, 0), (-1, 0), (0, 1), (0, -1)]
                for (dr, dc) in directions:
                    row, col = r + dr, c + dc

                    if row in range(n) and col in range(m) and grid[row][col] == 1:
                        q.append((row, col))
                        grid[row][col] = 2
                        rotten += 1

            if q:
                level += 1

        return level if fresh==rotten else -1