n = int(input()) M = [] for _ in range(n): M.append(list(map(int, input().split()))) max_len = 0 def dfs_r(x,y,max_r): # 寻找右边界 if y < n: if M[x][y] == 0: return max_r,y return dfs_r(x, y+1,max_r+1) else: return max_r,y-1 def dfs_b(x,y,max_b): # 寻...