Buggy python submission (verdict: Time Limit Exceeded):
import collections
h,w = map(int,input().split())
q = collections.deque()
A = []
for i in range(h):
    s = input()
    L = []
    for j in range(w):
        if s[j] == '.':
            L.append(s[j])
        else:
            L.append(0)
            q.append([i,j])
    A.append(L)
dy_dx = [[1,0],[0,1],[-1,0],[0,-1]]
while len(q) > 0:
    cur = q.popleft()
    for i in range(4):
        y = cur[0]+dy_dx[i][0]
        x = cur[1]+dy_dx[i][1]
        if 0 <= y < h and 0 <= x < w:
            if A[y][x] == '.':
                A[y][x] = A[cur[0]][cur[1]]+1
                q.append([y,x])
ans = 0
for i in range(h):
    for j in range(w):
        if ans < A[i][j]:
            ans = A[i][j]
print(ans)

Fixed submission:
import collections
h,w = map(int,input().split())
q = collections.deque()
A = []
for i in range(h):
    s = input()
    L = []
    for j in range(w):
        if s[j] == '.':
            L.append(s[j])
        else:
            L.append(0)
            q.append([i,j])
    A.append(L)
dy_dx = [[1,0],[0,1],[-1,0],[0,-1]]
while len(q) > 0:
    cur = q.popleft()
    for i in range(4):
        y = cur[0]+dy_dx[i][0]
        x = cur[1]+dy_dx[i][1]
        if 0 <= y < h and 0 <= x < w:
            if A[y][x] == '.':
                A[y][x] = A[cur[0]][cur[1]]+1
                q.append([y,x])
ans = 0
for i in range(h):
    for j in range(w):
        if ans < A[i][j]:
            ans = A[i][j]
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
import collections
h,w = map(int,input().split())
q = collections.deque()
ans = 0
A = []
for i in range(h):
    s = input()
    L = []
    for j in range(w):
        L.append(s[j])
        if s[j] == '#':
            q.append([i,j])
    A.append(L)
dy_dx = [[1,0],[0,1],[-1,0],[0,-1]]
t = len(q)
while len(q) > 0:
    cur = q.popleft()
    for i in range(4):
        y = cur[0]+dy_dx[i][0]
        x = cur[1]+dy_dx[i][1]
        if 0 <= y < h and 0 <= x < w:
            if A[y][x] == '.':
                A[y][x] = '#'
                q.append([y,x])
    if t > 0:
        t -= 1
    else:
        t = len(q)
        ans += 1
print(ans)

Fixed submission:
import collections
h,w = map(int,input().split())
q = collections.deque()
A = []
for i in range(h):
    s = input()
    L = []
    for j in range(w):
        if s[j] == '.':
            L.append(s[j])
        else:
            L.append(0)
            q.append([i,j])
    A.append(L)
dy_dx = [[1,0],[0,1],[-1,0],[0,-1]]
while len(q) > 0:
    cur = q.popleft()
    for i in range(4):
        y = cur[0]+dy_dx[i][0]
        x = cur[1]+dy_dx[i][1]
        if 0 <= y < h and 0 <= x < w:
            if A[y][x] == '.':
                A[y][x] = A[cur[0]][cur[1]]+1
                q.append([y,x])
ans = 0
for i in range(h):
    for j in range(w):
        if ans < A[i][j]:
            ans = A[i][j]
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
h,w = map(int,input().split())
L = []
for i in range(h):
  L.append(tuple(input()))
B = []
W = []
for i in range(h):
  for j in range(w):
    if L[i][j] == '.':
      W.append((i,j))
    else:
      B.append((i,j))
anslist = []
for i in range(len(W)):
  ans = float('inf')
  for j in range(len(B)):
    if ans >= abs(W[i][0]-B[j][0])+abs(W[i][1]-B[j][1]):
      ans = abs(W[i][0]-B[j][0])+abs(W[i][1]-B[j][1])
  anslist.append(ans)
if len(anslist) != 0:
  print(max(anslist))
else:
  print(0)

Fixed submission:
import collections
h,w = map(int,input().split())
q = collections.deque()
A = []
for i in range(h):
    s = input()
    L = []
    for j in range(w):
        if s[j] == '.':
            L.append(s[j])
        else:
            L.append(0)
            q.append([i,j])
    A.append(L)
dy_dx = [[1,0],[0,1],[-1,0],[0,-1]]
while len(q) > 0:
    cur = q.popleft()
    for i in range(4):
        y = cur[0]+dy_dx[i][0]
        x = cur[1]+dy_dx[i][1]
        if 0 <= y < h and 0 <= x < w:
            if A[y][x] == '.':
                A[y][x] = A[cur[0]][cur[1]]+1
                q.append([y,x])
ans = 0
for i in range(h):
    for j in range(w):
        if ans < A[i][j]:
            ans = A[i][j]
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
h,w = map(int,input().split())
L = []
for i in range(h):
  L.append(list(input()))
B = []
W = []
for i in range(h):
  for j in range(w):
    if L[i][j] == '.':
      W.append([i,j])
    else:
      B.append([i,j])
anslist = []
for i in range(len(W)):
  ans = float('inf')
  for j in range(len(B)):
    if ans >= abs(W[i][0]-B[j][0])+abs(W[i][1]-B[j][1]):
      ans = abs(W[i][0]-B[j][0])+abs(W[i][1]-B[j][1])
  anslist.append(ans)
if len(anslist) != 0:
  print(max(anslist))
else:
  print(0)

Fixed submission:
import collections
h,w = map(int,input().split())
q = collections.deque()
A = []
for i in range(h):
    s = input()
    L = []
    for j in range(w):
        if s[j] == '.':
            L.append(s[j])
        else:
            L.append(0)
            q.append([i,j])
    A.append(L)
dy_dx = [[1,0],[0,1],[-1,0],[0,-1]]
while len(q) > 0:
    cur = q.popleft()
    for i in range(4):
        y = cur[0]+dy_dx[i][0]
        x = cur[1]+dy_dx[i][1]
        if 0 <= y < h and 0 <= x < w:
            if A[y][x] == '.':
                A[y][x] = A[cur[0]][cur[1]]+1
                q.append([y,x])
ans = 0
for i in range(h):
    for j in range(w):
        if ans < A[i][j]:
            ans = A[i][j]
print(ans)

Buggy python submission (verdict: Runtime Error):
h,w = map(int,input().split())
L = []
for i in range(h):
  L.append(list(input()))
B = []
W = []
for i in range(h):
  for j in range(w):
    if L[i][j] == '.':
      W.append([i,j])
    else:
      B.append([i,j])
anslist = []
for i in range(len(W)):
  ans = float('inf')
  for j in range(len(B)):
    if ans >= abs(W[i][0]-B[j][0])+abs(W[i][1]-B[j][1]):
      ans = abs(W[i][0]-B[j][0])+abs(W[i][1]-B[j][1])
  anslist.append(ans)
print(max(anslist))

Fixed submission:
import collections
h,w = map(int,input().split())
q = collections.deque()
A = []
for i in range(h):
    s = input()
    L = []
    for j in range(w):
        if s[j] == '.':
            L.append(s[j])
        else:
            L.append(0)
            q.append([i,j])
    A.append(L)
dy_dx = [[1,0],[0,1],[-1,0],[0,-1]]
while len(q) > 0:
    cur = q.popleft()
    for i in range(4):
        y = cur[0]+dy_dx[i][0]
        x = cur[1]+dy_dx[i][1]
        if 0 <= y < h and 0 <= x < w:
            if A[y][x] == '.':
                A[y][x] = A[cur[0]][cur[1]]+1
                q.append([y,x])
ans = 0
for i in range(h):
    for j in range(w):
        if ans < A[i][j]:
            ans = A[i][j]
print(ans)

Buggy python submission (verdict: Runtime Error):
h,w = map(int,input().split())
L = []
for i in range(h):
  L.append(list(input()))
B = []
W = []
for i in range(h):
  for j in range(w):
    if L[i][j] == '.':
      W.append([i,j])
    else:
      B.append([i,j])
anslist = []
for i in range(len(W)):
  ans = float('inf')
  for j in range(len(B)):
    if ans >= abs(W[i][0]-B[j][0])+abs(W[i][1]-B[j][1]):
      ans = abs(W[i][0]-B[j][0])+abs(W[i][1]-B[j][1])
  anslist.append(ans)
print(max(anslist))

Fixed submission:
import collections
h,w = map(int,input().split())
q = collections.deque()
A = []
for i in range(h):
    s = input()
    L = []
    for j in range(w):
        if s[j] == '.':
            L.append(s[j])
        else:
            L.append(0)
            q.append([i,j])
    A.append(L)
dy_dx = [[1,0],[0,1],[-1,0],[0,-1]]
while len(q) > 0:
    cur = q.popleft()
    for i in range(4):
        y = cur[0]+dy_dx[i][0]
        x = cur[1]+dy_dx[i][1]
        if 0 <= y < h and 0 <= x < w:
            if A[y][x] == '.':
                A[y][x] = A[cur[0]][cur[1]]+1
                q.append([y,x])
ans = 0
for i in range(h):
    for j in range(w):
        if ans < A[i][j]:
            ans = A[i][j]
print(ans)