岛屿数量

def solve(____):
    grid = [list(____) for row in grid.split(____)]
    m, n = len(____), len(____)
    count = ____
    def dfs(____):
        if ____ <= r < m and ____ <= c < n and grid[r][c] == '____':
            grid[r][c] = '____'
            dfs(____)
            dfs(____)
            dfs(____)
            dfs(____)
    for i in range(____):
        for j in range(____):
            if grid[i][j] == '____':
                count += ____
                dfs(____)
    print(____)