h, w = map(int, input().split()) g = [[-1 for _ in range(w)] for _ in range(h)] for i in range(h): line = list(map(int, input().split())) for j in range(w): g[i][j] = line[j] # h=5 # w=5 # g=[ # [0,1,0,0,0], # [0,1,0,1,0], # [0,0,0,0,1], # [0,1,1,1,0], # [0,0,0,0,0] # ] visited = [[False for _ in ra...