class Solution:
    def orangesRotting(self, grid: List[List[int]]) -> int:
        rows, cols = len(grid), len(grid[0])
        q = collections.deque()
        time = 0
        total_fresh = 0
        count_fresh = 0

        for r in range(rows):
            for c in range(cols):
                if grid[r][c] == 1:
                    total_fresh += 1
                if grid[r][c] == 2:
                    q.append((r, c))

        directions = [[0, 1], [0, -1], [1, 0], [-1, 0]]
        while(q) and total_fresh!=count_fresh:
            size = len(q)
            for _ in range(size):
                r, c = q.popleft()
                for dr, dc in directions:
                    row = r + dr
                    col = c + dc
                    if row in range(rows) and col in range(cols) and grid[row][col] == 1:
                        grid[row][col] = 2
                        q.append((row, col))
                        count_fresh += 1
            time = time + 1

        return -1 if total_fresh!=count_fresh else time