황소개발자

import sys input = sys.stdin.readline h, w = map(int, input().split()) mat = [[] for i in range(h)] dx = [1, -1 , 0, 0] dy = [0, 0, 1, -1] for i in range(h): ss = input().strip() for s in ss: mat[i].append(int(s)) def bfs(y, x): q = [[y, x]] while q: now = q.pop(0) for i in range(4): ny = now[0] + dy[i] nx = now[1] + dx[i] if 0