Buggy python submission (verdict: Time Limit Exceeded):
def main():
  import collections
  import sys
  input = sys.stdin.readline
  H, W = map(int, input().split())
  A = [list(input()) for i in range(H)]
  dp = [[-1]*W for i in range(H)]

  q = collections.deque()
  for i in range(H):
    for j in range(W):
      if A[i][j] == "#":
          dp[i][j] = 0
          q.append([i, j])


  while(q):
    x, y = q.popleft()
    if x > 0:
      if dp[x-1][y] == -1:
          dp[x-1][y] = dp[x][y]+1
          q.append([x-1, y])
    if x < H-1:
      if dp[x+1][y] == -1:
          dp[x+1][y] = dp[x][y]+1
          q.append([x+1, y])
    if y > 0:
      if dp[x][y-1] == -1:
          dp[x][y-1] = dp[x][y]+1
          q.append([x, y-1])
    if y < W-1:
      if dp[x][y+1] == -1:
          dp[x][y+1] = dp[x][y]+1
          q.append([x, y+1])
  ans = 0
  for i in range(H):
    ans = max(ans, max(dp[i]))
  print(ans)
main()


Fixed submission:
import collections
import sys
input = sys.stdin.readline
H, W = map(int, input().split())
A = [list(input()) for i in range(H)]
dp = [[H+W]*W for i in range(H)]

q = collections.deque()
for i in range(H):
    for j in range(W):
        if A[i][j] == "#":
            dp[i][j] = 0
            q.append([i, j])
            break
    if q:
        break


while(q):
    x, y = q.popleft()
    if x > 0:
        if dp[x-1][y] > dp[x][y]+1:
            if A[x-1][y] == ".":
                dp[x-1][y] = dp[x][y]+1
            else:
                dp[x-1][y] = 0
            q.append([x-1, y])
    if x < H-1:
        if dp[x+1][y] > dp[x][y]+1:
            if A[x+1][y] == ".":
                dp[x+1][y] = dp[x][y]+1
            else:
                dp[x+1][y] = 0
            q.append([x+1, y])
    if y > 0:
        if dp[x][y-1] > dp[x][y]+1:
            if A[x][y-1] == ".":
                dp[x][y-1] = dp[x][y]+1
            else:
                dp[x][y-1] = 0
            q.append([x, y-1])
    if y < W-1:
        if dp[x][y+1] > dp[x][y]+1:
            if A[x][y+1] == ".":
                dp[x][y+1] = dp[x][y]+1
            else:
                dp[x][y+1] = 0
            q.append([x, y+1])
ans = 0
for i in range(H):
    ans = max(ans, max(dp[i]))
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
import collections
import sys
input = sys.stdin.readline
H, W = map(int, input().split())
A = [list(input()) for i in range(H)]
dp = [[-1]*W for i in range(H)]

q = collections.deque()
for i in range(H):
    for j in range(W):
        if A[i][j] == "#":
            dp[i][j] = 0
            q.append([i, j])


while(q):
    x, y = q.popleft()
    if x > 0:
        if dp[x-1][y] == -1:
            dp[x-1][y] = dp[x][y]+1
            q.append([x-1, y])
    if x < H-1:
        if dp[x+1][y] == -1:
            dp[x+1][y] = dp[x][y]+1
            q.append([x+1, y])
    if y > 0:
        if dp[x][y-1] == -1:
            dp[x][y-1] = dp[x][y]+1
            q.append([x, y-1])
    if y < W-1:
        if dp[x][y+1] == -1:
            dp[x][y+1] = dp[x][y]+1
            q.append([x, y+1])
ans = 0
for i in range(H):
    ans = max(ans, max(dp[i]))
print(ans)


Fixed submission:
import collections
import sys
input = sys.stdin.readline
H, W = map(int, input().split())
A = [list(input()) for i in range(H)]
dp = [[H+W]*W for i in range(H)]

q = collections.deque()
for i in range(H):
    for j in range(W):
        if A[i][j] == "#":
            dp[i][j] = 0
            q.append([i, j])
            break
    if q:
        break


while(q):
    x, y = q.popleft()
    if x > 0:
        if dp[x-1][y] > dp[x][y]+1:
            if A[x-1][y] == ".":
                dp[x-1][y] = dp[x][y]+1
            else:
                dp[x-1][y] = 0
            q.append([x-1, y])
    if x < H-1:
        if dp[x+1][y] > dp[x][y]+1:
            if A[x+1][y] == ".":
                dp[x+1][y] = dp[x][y]+1
            else:
                dp[x+1][y] = 0
            q.append([x+1, y])
    if y > 0:
        if dp[x][y-1] > dp[x][y]+1:
            if A[x][y-1] == ".":
                dp[x][y-1] = dp[x][y]+1
            else:
                dp[x][y-1] = 0
            q.append([x, y-1])
    if y < W-1:
        if dp[x][y+1] > dp[x][y]+1:
            if A[x][y+1] == ".":
                dp[x][y+1] = dp[x][y]+1
            else:
                dp[x][y+1] = 0
            q.append([x, y+1])
ans = 0
for i in range(H):
    ans = max(ans, max(dp[i]))
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
import collections
import sys
input = sys.stdin.readline
H, W = map(int, input().split())
A = [list(input()) for i in range(H)]
dp = [[H+W]*W for i in range(H)]

q = collections.deque()
for i in range(H):
    for j in range(W):
        if A[i][j] == "#":
            dp[i][j] = 0
            q.append([i, j])


while(q):
    x, y = q.popleft()
    if x > 0:
        if dp[x-1][y] > dp[x][y]+1:
            if A[x-1][y] == ".":
                dp[x-1][y] = dp[x][y]+1
            else:
                dp[x-1][y] = 0
            q.append([x-1, y])
    if x < H-1:
        if dp[x+1][y] > dp[x][y]+1:
            if A[x+1][y] == ".":
                dp[x+1][y] = dp[x][y]+1
            else:
                dp[x+1][y] = 0
            q.append([x+1, y])
    if y > 0:
        if dp[x][y-1] > dp[x][y]+1:
            if A[x][y-1] == ".":
                dp[x][y-1] = dp[x][y]+1
            else:
                dp[x][y-1] = 0
            q.append([x, y-1])
    if y < W-1:
        if dp[x][y+1] > dp[x][y]+1:
            if A[x][y+1] == ".":
                dp[x][y+1] = dp[x][y]+1
            else:
                dp[x][y+1] = 0
            q.append([x, y+1])
ans = 0
for i in range(H):
    ans = max(ans, max(dp[i]))
print(ans)


Fixed submission:
import collections
import sys
input = sys.stdin.readline
H, W = map(int, input().split())
A = [list(input()) for i in range(H)]
dp = [[H+W]*W for i in range(H)]

q = collections.deque()
for i in range(H):
    for j in range(W):
        if A[i][j] == "#":
            dp[i][j] = 0
            q.append([i, j])
            break
    if q:
        break


while(q):
    x, y = q.popleft()
    if x > 0:
        if dp[x-1][y] > dp[x][y]+1:
            if A[x-1][y] == ".":
                dp[x-1][y] = dp[x][y]+1
            else:
                dp[x-1][y] = 0
            q.append([x-1, y])
    if x < H-1:
        if dp[x+1][y] > dp[x][y]+1:
            if A[x+1][y] == ".":
                dp[x+1][y] = dp[x][y]+1
            else:
                dp[x+1][y] = 0
            q.append([x+1, y])
    if y > 0:
        if dp[x][y-1] > dp[x][y]+1:
            if A[x][y-1] == ".":
                dp[x][y-1] = dp[x][y]+1
            else:
                dp[x][y-1] = 0
            q.append([x, y-1])
    if y < W-1:
        if dp[x][y+1] > dp[x][y]+1:
            if A[x][y+1] == ".":
                dp[x][y+1] = dp[x][y]+1
            else:
                dp[x][y+1] = 0
            q.append([x, y+1])
ans = 0
for i in range(H):
    ans = max(ans, max(dp[i]))
print(ans)

Buggy python submission (verdict: Runtime Error):
import collections
import sys
input = sys.stdin.readline
H, W = map(int, input().split())
A = [list(input()) for i in range(H)]

dis = [[-1]*W for i in range(H)]
black = set()
white = set()

start = [-1, -1]

for i in range(H):
    for j in range(W):
        if A[i][j] == "#":
            start[0] = i
            start[1] = j

            break
    if start[0] != -1:
        break


dp = [[H+W]*W for i in range(H)]


q = collections.deque([start])
dp[start[0]][start[1]] = 0
count = 0
while(q):
    x, y = q.popleft()
    if x > 0:
        if dp[x-1][y] > dp[x][y]+1:
            if A[x-1][y] == ".":
                dp[x-1][y] = dp[x][y]+1
            else:
                dp[x-1][y] = 0
            q.append([x-1, y])
    if x < W-1:
        if dp[x+1][y] > dp[x][y]+1:
            if A[x+1][y] == ".":
                dp[x+1][y] = dp[x][y]+1
            else:
                dp[x+1][y] = 0
            q.append([x+1, y])
    if y > 0:
        if dp[x][y-1] > dp[x][y]+1:
            if A[x][y-1] == ".":
                dp[x][y-1] = dp[x][y]+1
            else:
                dp[x][y-1] = 0
            q.append([x, y-1])
    if y < H-1:
        if dp[x][y+1] > dp[x][y]+1:
            if A[x][y+1] == ".":
                dp[x][y+1] = dp[x][y]+1
            else:
                dp[x][y+1] = 0
            q.append([x, y+1])
ans = 0
for i in range(H):
    ans = max(ans, max(dp[i]))
print(ans)


Fixed submission:
import collections
import sys
input = sys.stdin.readline
H, W = map(int, input().split())
A = [list(input()) for i in range(H)]
dp = [[H+W]*W for i in range(H)]

q = collections.deque()
for i in range(H):
    for j in range(W):
        if A[i][j] == "#":
            dp[i][j] = 0
            q.append([i, j])
            break
    if q:
        break


while(q):
    x, y = q.popleft()
    if x > 0:
        if dp[x-1][y] > dp[x][y]+1:
            if A[x-1][y] == ".":
                dp[x-1][y] = dp[x][y]+1
            else:
                dp[x-1][y] = 0
            q.append([x-1, y])
    if x < H-1:
        if dp[x+1][y] > dp[x][y]+1:
            if A[x+1][y] == ".":
                dp[x+1][y] = dp[x][y]+1
            else:
                dp[x+1][y] = 0
            q.append([x+1, y])
    if y > 0:
        if dp[x][y-1] > dp[x][y]+1:
            if A[x][y-1] == ".":
                dp[x][y-1] = dp[x][y]+1
            else:
                dp[x][y-1] = 0
            q.append([x, y-1])
    if y < W-1:
        if dp[x][y+1] > dp[x][y]+1:
            if A[x][y+1] == ".":
                dp[x][y+1] = dp[x][y]+1
            else:
                dp[x][y+1] = 0
            q.append([x, y+1])
ans = 0
for i in range(H):
    ans = max(ans, max(dp[i]))
print(ans)

Buggy python submission (verdict: Runtime Error):
import collections
import sys
input = sys.stdin.readline
H, W = map(int, input().split())
A = [list(input()) for i in range(H)]

dis = [[-1]*W for i in range(H)]
black = set()
white = set()

start = [-1, -1]

for i in range(H):
    for j in range(W):
        if A[i][j] == "#":
            start[0] = i
            start[1] = j

            break
    if start[0] != -1:
        break


dp = [[10**9]*W for i in range(H)]


q = collections.deque([start])
dp[start[0]][start[1]] = 0
count = 0
while(q):
    x, y = q.popleft()
    if x > 0:
        if dp[x-1][y] > dp[x][y]+1:
            if A[x-1][y] == ".":
                dp[x-1][y] = dp[x][y]+1
            else:
                dp[x-1][y] = 0
            q.append([x-1, y])
    if x < W-1:
        if dp[x+1][y] > dp[x][y]+1:
            if A[x+1][y] == ".":
                dp[x+1][y] = dp[x][y]+1
            else:
                dp[x+1][y] = 0
            q.append([x+1, y])
    if y > 0:
        if dp[x][y-1] > dp[x][y]+1:
            if A[x][y-1] == ".":
                dp[x][y-1] = dp[x][y]+1
            else:
                dp[x][y-1] = 0
            q.append([x, y-1])
    if y < H-1:
        if dp[x][y+1] > dp[x][y]+1:
            if A[x][y+1] == ".":
                dp[x][y+1] = dp[x][y]+1
            else:
                dp[x][y+1] = 0
            q.append([x, y+1])
ans = 0
for i in range(H):
    ans = max(ans, max(dp[i]))
print(ans)


Fixed submission:
import collections
import sys
input = sys.stdin.readline
H, W = map(int, input().split())
A = [list(input()) for i in range(H)]
dp = [[H+W]*W for i in range(H)]

q = collections.deque()
for i in range(H):
    for j in range(W):
        if A[i][j] == "#":
            dp[i][j] = 0
            q.append([i, j])
            break
    if q:
        break


while(q):
    x, y = q.popleft()
    if x > 0:
        if dp[x-1][y] > dp[x][y]+1:
            if A[x-1][y] == ".":
                dp[x-1][y] = dp[x][y]+1
            else:
                dp[x-1][y] = 0
            q.append([x-1, y])
    if x < H-1:
        if dp[x+1][y] > dp[x][y]+1:
            if A[x+1][y] == ".":
                dp[x+1][y] = dp[x][y]+1
            else:
                dp[x+1][y] = 0
            q.append([x+1, y])
    if y > 0:
        if dp[x][y-1] > dp[x][y]+1:
            if A[x][y-1] == ".":
                dp[x][y-1] = dp[x][y]+1
            else:
                dp[x][y-1] = 0
            q.append([x, y-1])
    if y < W-1:
        if dp[x][y+1] > dp[x][y]+1:
            if A[x][y+1] == ".":
                dp[x][y+1] = dp[x][y]+1
            else:
                dp[x][y+1] = 0
            q.append([x, y+1])
ans = 0
for i in range(H):
    ans = max(ans, max(dp[i]))
print(ans)

Buggy python submission (verdict: Runtime Error):
import collections
import sys
input = sys.stdin.readline
H, W = map(int, input().split())
A = [list(input()) for i in range(H)]

dis = [[-1]*W for i in range(H)]
black = set()
white = set()

start = [-1, -1]

for i in range(H):
    for j in range(W):
        if A[i][j] == "#":
            start[0] = i
            start[1] = j

            break
    if start[0] != -1:
        break


dp = [[10**9]*W for i in range(H)]


q = collections.deque([start])
dp[start[0]][start[1]] = 0
count = 0
while(q):
    x, y = q.popleft()
    if x > 0:
        if dp[x-1][y] > dp[x][y]+1:
            if A[x-1][y] == ".":
                dp[x-1][y] = dp[x][y]+1
            else:
                dp[x-1][y] = 0
            q.append([x-1, y])
    if x < W-1:
        if dp[x+1][y] > dp[x][y]+1:
            if A[x+1][y] == ".":
                dp[x+1][y] = dp[x][y]+1
            else:
                dp[x+1][y] = 0
            q.append([x+1, y])
    if y > 0:
        if dp[x][y-1] > dp[x][y]+1:
            if A[x][y-1] == ".":
                dp[x][y-1] = dp[x][y]+1
            else:
                dp[x][y-1] = 0
            q.append([x, y-1])
    if y < H-1:
        if dp[x][y+1] > dp[x][y]+1:
            if A[x][y+1] == ".":
                dp[x][y+1] = dp[x][y]+1
            else:
                dp[x][y+1] = 0
            q.append([x, y+1])
ans = 0
for i in range(H):
    ans = max(ans, max(dp[i]))
print(ans)


Fixed submission:
import collections
import sys
input = sys.stdin.readline
H, W = map(int, input().split())
A = [list(input()) for i in range(H)]
dp = [[H+W]*W for i in range(H)]

q = collections.deque()
for i in range(H):
    for j in range(W):
        if A[i][j] == "#":
            dp[i][j] = 0
            q.append([i, j])
            break
    if q:
        break


while(q):
    x, y = q.popleft()
    if x > 0:
        if dp[x-1][y] > dp[x][y]+1:
            if A[x-1][y] == ".":
                dp[x-1][y] = dp[x][y]+1
            else:
                dp[x-1][y] = 0
            q.append([x-1, y])
    if x < H-1:
        if dp[x+1][y] > dp[x][y]+1:
            if A[x+1][y] == ".":
                dp[x+1][y] = dp[x][y]+1
            else:
                dp[x+1][y] = 0
            q.append([x+1, y])
    if y > 0:
        if dp[x][y-1] > dp[x][y]+1:
            if A[x][y-1] == ".":
                dp[x][y-1] = dp[x][y]+1
            else:
                dp[x][y-1] = 0
            q.append([x, y-1])
    if y < W-1:
        if dp[x][y+1] > dp[x][y]+1:
            if A[x][y+1] == ".":
                dp[x][y+1] = dp[x][y]+1
            else:
                dp[x][y+1] = 0
            q.append([x, y+1])
ans = 0
for i in range(H):
    ans = max(ans, max(dp[i]))
print(ans)

Buggy python submission (verdict: Runtime Error):
import collections
H, W = map(int, input().split())
A = [list(input()) for i in range(H)]

dis = [[-1]*W for i in range(H)]
black = set()
white = set()

start = [-1, -1]

for i in range(H):
    for j in range(W):
        if A[i][j] == "#":
            start[0] = i
            start[1] = j

            break
    if start[0] != -1:
        break


dp = [[10**9]*W for i in range(H)]


q = collections.deque([start])
dp[start[0]][start[1]] = 0
while(q):
    x, y = q.popleft()
    if x > 0:
        if dp[x-1][y] > dp[x][y]+1:
            if A[x-1][y] == ".":
                dp[x-1][y] = dp[x][y]+1
            else:
                dp[x-1][y] = 0
            q.append([x-1, y])
    if x < W-1:
        if dp[x+1][y] > dp[x][y]+1:
            if A[x+1][y] == ".":
                dp[x+1][y] = dp[x][y]+1
            else:
                dp[x+1][y] = 0
            q.append([x+1, y])
    if y > 0:
        if dp[x][y-1] > dp[x][y]+1:
            if A[x][y-1] == ".":
                dp[x][y-1] = dp[x][y]+1
            else:
                dp[x][y-1] = 0
            q.append([x, y-1])
    if y < H-1:
        if dp[x][y+1] > dp[x][y]+1:
            if A[x][y+1] == ".":
                dp[x][y+1] = dp[x][y]+1
            else:
                dp[x][y+1] = 0
            q.append([x, y+1])
ans = 0
for i in range(H):
    ans = max(ans, max(dp[i]))

print(ans)


Fixed submission:
import collections
import sys
input = sys.stdin.readline
H, W = map(int, input().split())
A = [list(input()) for i in range(H)]
dp = [[H+W]*W for i in range(H)]

q = collections.deque()
for i in range(H):
    for j in range(W):
        if A[i][j] == "#":
            dp[i][j] = 0
            q.append([i, j])
            break
    if q:
        break


while(q):
    x, y = q.popleft()
    if x > 0:
        if dp[x-1][y] > dp[x][y]+1:
            if A[x-1][y] == ".":
                dp[x-1][y] = dp[x][y]+1
            else:
                dp[x-1][y] = 0
            q.append([x-1, y])
    if x < H-1:
        if dp[x+1][y] > dp[x][y]+1:
            if A[x+1][y] == ".":
                dp[x+1][y] = dp[x][y]+1
            else:
                dp[x+1][y] = 0
            q.append([x+1, y])
    if y > 0:
        if dp[x][y-1] > dp[x][y]+1:
            if A[x][y-1] == ".":
                dp[x][y-1] = dp[x][y]+1
            else:
                dp[x][y-1] = 0
            q.append([x, y-1])
    if y < W-1:
        if dp[x][y+1] > dp[x][y]+1:
            if A[x][y+1] == ".":
                dp[x][y+1] = dp[x][y]+1
            else:
                dp[x][y+1] = 0
            q.append([x, y+1])
ans = 0
for i in range(H):
    ans = max(ans, max(dp[i]))
print(ans)