Buggy python submission (verdict: Runtime Error):
import numpy as np

H, W = map(int, input().split())

x = []
for h in range(H):
    line = list(input())
    for _ in line:
        for value in _:
            x.append(value)
x = np.array(x)
x = x.reshape(num_i, num_j)

count = 0
boolean = True
while (boolean):
    count += 1
    i_arr = []
    j_arr = []
    for i in range(num_i):
        for j in range(num_j):
            if (x[i][j] == "#"):
                i_arr.append(i)
                j_arr.append(j)
    for i, j in zip(i_arr, j_arr):
        if (i == 0) & (j == 0):
            x[1][0] = "#"
            x[0][1] = "#"
        elif (i == num_i - 1) & (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i][j - 1] = "#"
        elif (i == num_i - 1) & (j == 0):
            x[i - 1][0] = "#"
            x[i][1] = "#"
        elif (i == 0) & (j == num_j - 1):
            x[1][j] = "#"
            x[0][j - 1] = "#"
        elif (i == 0):
            x[1][j] = "#"
            x[0][j - 1] = "#"
            x[0][j + 1] = "#"
        elif (j == 0):
            x[i - 1][0] = "#"
            x[i + 1][0] = "#"
            x[i][1] = "#"
        elif (i == num_i - 1):
            x[i - 1][j] = "#"
            x[i][j + 1] = "#"
            x[i][j - 1] = "#"
        elif (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
        else:
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
            x[i][j + 1] = "#"
    if len(set(list(x.flatten()))) == 1:
        boolean = False
    else:
        boolean = True

print(count)

Fixed submission:
from collections import deque

H, W = map(int, input().split())

# input black cells
black_cells = []

for h in range(H):
    line = list(input())
    for w in range(W):
        if line[w] == "#":
            black_cells.append(h * W + w)


# Graph
def r(p):
    q_list = []
    h = p // W
    w = p % W
    if h != 0:
        q_list.append(p - W)
    if h != H-1:
        q_list.append(p + W)
    if w != 0:
        q_list.append(p - 1)
    if w != W-1:
        q_list.append(p + 1)
    return q_list


queue = deque(black_cells)
d = [10000] * (H * W)
for i in black_cells:
    d[i] = 0

# dijkstra
while len(queue) > 0:
    p = queue.popleft()
    for q in r(p):
        if d[q] > d[p] + 1:
            d[q] = d[p] + 1
            queue.append(q)

print(max(d))

Buggy python submission (verdict: Runtime Error):
import numpy as np

H, W = map(int, input().split())

x = []
for h in range(H):
    line = list(input())
    for _ in line:
        for value in _:
            x.append(value)
x = np.array(x)
x = x.reshape(num_i, num_j)

count = 0
boolean = True
while (boolean):
    count += 1
    i_arr = []
    j_arr = []
    for i in range(num_i):
        for j in range(num_j):
            if (x[i][j] == "#"):
                i_arr.append(i)
                j_arr.append(j)
    for i, j in zip(i_arr, j_arr):
        if (i == 0) & (j == 0):
            x[1][0] = "#"
            x[0][1] = "#"
        elif (i == num_i - 1) & (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i][j - 1] = "#"
        elif (i == num_i - 1) & (j == 0):
            x[i - 1][0] = "#"
            x[i][1] = "#"
        elif (i == 0) & (j == num_j - 1):
            x[1][j] = "#"
            x[0][j - 1] = "#"
        elif (i == 0):
            x[1][j] = "#"
            x[0][j - 1] = "#"
            x[0][j + 1] = "#"
        elif (j == 0):
            x[i - 1][0] = "#"
            x[i + 1][0] = "#"
            x[i][1] = "#"
        elif (i == num_i - 1):
            x[i - 1][j] = "#"
            x[i][j + 1] = "#"
            x[i][j - 1] = "#"
        elif (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
        else:
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
            x[i][j + 1] = "#"
    if len(set(list(x.flatten()))) == 1:
        boolean = False
    else:
        boolean = True

print(str(count))

Fixed submission:
from collections import deque

H, W = map(int, input().split())

# input black cells
black_cells = []

for h in range(H):
    line = list(input())
    for w in range(W):
        if line[w] == "#":
            black_cells.append(h * W + w)


# Graph
def r(p):
    q_list = []
    h = p // W
    w = p % W
    if h != 0:
        q_list.append(p - W)
    if h != H-1:
        q_list.append(p + W)
    if w != 0:
        q_list.append(p - 1)
    if w != W-1:
        q_list.append(p + 1)
    return q_list


queue = deque(black_cells)
d = [10000] * (H * W)
for i in black_cells:
    d[i] = 0

# dijkstra
while len(queue) > 0:
    p = queue.popleft()
    for q in r(p):
        if d[q] > d[p] + 1:
            d[q] = d[p] + 1
            queue.append(q)

print(max(d))

Buggy python submission (verdict: Runtime Error):
import numpy as np
from scipy import ndimage

H, W = map(int, input().split())

A_array = np.array(
    [[0 if s == "#" else 1 for s in input()[:-1]] for i in range(H)])


b = ndimage.morphology.distance_transform_cdt(
    A_array, metric="taxicab")
print(np.max(b))

Fixed submission:
from collections import deque

H, W = map(int, input().split())

# input black cells
black_cells = []

for h in range(H):
    line = list(input())
    for w in range(W):
        if line[w] == "#":
            black_cells.append(h * W + w)


# Graph
def r(p):
    q_list = []
    h = p // W
    w = p % W
    if h != 0:
        q_list.append(p - W)
    if h != H-1:
        q_list.append(p + W)
    if w != 0:
        q_list.append(p - 1)
    if w != W-1:
        q_list.append(p + 1)
    return q_list


queue = deque(black_cells)
d = [10000] * (H * W)
for i in black_cells:
    d[i] = 0

# dijkstra
while len(queue) > 0:
    p = queue.popleft()
    for q in r(p):
        if d[q] > d[p] + 1:
            d[q] = d[p] + 1
            queue.append(q)

print(max(d))

Buggy python submission (verdict: Runtime Error):
import numpy as np

num_i, num_j = map(int, input().split())
inputs = [input() for i in range(num_i)]

x = []
for _ in inputs:
    for value in _:
        x.append(value)
x = np.array(x)
x = x.reshape(num_i, num_j)

count = 0
boolean = True
while (boolean):
    count += 1
    i_arr = []
    j_arr = []
    for i in range(num_i):
        for j in range(num_j):
            if (x[i][j] == "#"):
                i_arr.append(i)
                j_arr.append(j)
    for i, j in zip(i_arr, j_arr):
        if (i == 0) & (j == 0):
            x[1][0] = "#"
            x[0][1] = "#"
        elif (i == num_i - 1) & (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i][j - 1] = "#"
        elif (i == num_i - 1) & (j == 0):
            x[i - 1][0] = "#"
            x[i][1] = "#"
        elif (i == 0) & (j == num_j - 1):
            x[1][j] = "#"
            x[0][j - 1] = "#"
        elif (i == 0):
            x[1][j] = "#"
            x[0][j - 1] = "#"
            x[0][j + 1] = "#"
        elif (j == 0):
            x[i - 1][0] = "#"
            x[i + 1][0] = "#"
            x[i][1] = "#"
        elif (i == num_i - 1):
            x[i - 1][j] = "#"
            x[i][j + 1] = "#"
            x[i][j - 1] = "#"
        elif (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
        else:
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
            x[i][j + 1] = "#"
    if len(set(list(x.flatten()))) == 1:
        print(str(count))
        boolean = False
    else:
        boolean = True

Fixed submission:
from collections import deque

H, W = map(int, input().split())

# input black cells
black_cells = []

for h in range(H):
    line = list(input())
    for w in range(W):
        if line[w] == "#":
            black_cells.append(h * W + w)


# Graph
def r(p):
    q_list = []
    h = p // W
    w = p % W
    if h != 0:
        q_list.append(p - W)
    if h != H-1:
        q_list.append(p + W)
    if w != 0:
        q_list.append(p - 1)
    if w != W-1:
        q_list.append(p + 1)
    return q_list


queue = deque(black_cells)
d = [10000] * (H * W)
for i in black_cells:
    d[i] = 0

# dijkstra
while len(queue) > 0:
    p = queue.popleft()
    for q in r(p):
        if d[q] > d[p] + 1:
            d[q] = d[p] + 1
            queue.append(q)

print(max(d))

Buggy python submission (verdict: Runtime Error):
import numpy as np

num_i, num_j = map(int, input().split())
inputs = [input() for i in range(num_i)]

x = []
for _ in inputs:
    for value in _:
        x.append(value)
x = np.array(x)
x = x.reshape(num_i, num_j)

count = 0
boolean = True
while (boolean):
    count += 1
    i_arr = []
    j_arr = []
    for i in range(num_i):
        for j in range(num_j):
            if (x[i][j] == "#"):
                i_arr.append(i)
                j_arr.append(j)
    for i, j in zip(i_arr, j_arr):
        if (i == 0) & (j == 0):
            x[1][0] = "#"
            x[0][1] = "#"
        elif (i == num_i - 1) & (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i][j - 1] = "#"
        elif (i == num_i - 1) & (j == 0):
            x[i - 1][0] = "#"
            x[i][1] = "#"
        elif (i == 0) & (j == num_j - 1):
            x[1][j] = "#"
            x[0][j - 1] = "#"
        elif (i == 0):
            x[1][j] = "#"
            x[0][j - 1] = "#"
            x[0][j + 1] = "#"
        elif (j == 0):
            x[i - 1][0] = "#"
            x[i + 1][0] = "#"
            x[i][1] = "#"
        elif (i == num_i - 1):
            x[i - 1][j] = "#"
            x[i][j + 1] = "#"
            x[i][j - 1] = "#"
        elif (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
        else:
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
            x[i][j + 1] = "#"
    if len(set(list(x.flatten()))) == 1:
        print(str(count))
        boolean = False
    else:
        boolean = True

Fixed submission:
from collections import deque

H, W = map(int, input().split())

# input black cells
black_cells = []

for h in range(H):
    line = list(input())
    for w in range(W):
        if line[w] == "#":
            black_cells.append(h * W + w)


# Graph
def r(p):
    q_list = []
    h = p // W
    w = p % W
    if h != 0:
        q_list.append(p - W)
    if h != H-1:
        q_list.append(p + W)
    if w != 0:
        q_list.append(p - 1)
    if w != W-1:
        q_list.append(p + 1)
    return q_list


queue = deque(black_cells)
d = [10000] * (H * W)
for i in black_cells:
    d[i] = 0

# dijkstra
while len(queue) > 0:
    p = queue.popleft()
    for q in r(p):
        if d[q] > d[p] + 1:
            d[q] = d[p] + 1
            queue.append(q)

print(max(d))

Buggy python submission (verdict: Runtime Error):
import numpy as np

num_i, num_j = input().split(" ")
num_i = int(num_i)
num_j = int(num_j)
inputs = [input() for i in range(num_i)]


x = []
for _ in inputs:
    for value in _:
        x.append(value)
x = np.array(x)
x = x.reshape(num_i, num_j)

count = 0
boolean = True
while (boolean):
    count += 1
    i_arr = []
    j_arr = []
    for i in range(num_i):
        for j in range(num_j):
            if (x[i][j] == "#"):
                i_arr.append(i)
                j_arr.append(j)
    for i, j in zip(i_arr, j_arr):
        if (i == 0) & (j == 0):
            x[1][0] = "#"
            x[0][1] = "#"
        elif (i == num_i - 1) & (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i][j - 1] = "#"
        elif (i == num_i - 1) & (j == 0):
            x[i - 1][0] = "#"
            x[i][1] = "#"
        elif (i == 0) & (j == num_j - 1):
            x[1][j] = "#"
            x[0][j - 1] = "#"
        elif (i == 0):
            x[1][j] = "#"
            x[0][j - 1] = "#"
            x[0][j + 1] = "#"
        elif (j == 0):
            x[i - 1][0] = "#"
            x[i + 1][0] = "#"
            x[i][1] = "#"
        elif (i == num_i - 1):
            x[i - 1][j] = "#"
            x[i][j + 1] = "#"
            x[i][j - 1] = "#"
        elif (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
        else:
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
            x[i][j + 1] = "#"
    if len(set(list(x.flatten()))) == 1:
        print(str(count))
        boolean = False
    else:
        boolean = True

Fixed submission:
from collections import deque

H, W = map(int, input().split())

# input black cells
black_cells = []

for h in range(H):
    line = list(input())
    for w in range(W):
        if line[w] == "#":
            black_cells.append(h * W + w)


# Graph
def r(p):
    q_list = []
    h = p // W
    w = p % W
    if h != 0:
        q_list.append(p - W)
    if h != H-1:
        q_list.append(p + W)
    if w != 0:
        q_list.append(p - 1)
    if w != W-1:
        q_list.append(p + 1)
    return q_list


queue = deque(black_cells)
d = [10000] * (H * W)
for i in black_cells:
    d[i] = 0

# dijkstra
while len(queue) > 0:
    p = queue.popleft()
    for q in r(p):
        if d[q] > d[p] + 1:
            d[q] = d[p] + 1
            queue.append(q)

print(max(d))

Buggy python submission (verdict: Runtime Error):
import numpy as np

num_i, num_j = input().split(" ")
num_i = int(num_i)
num_j = int(num_j)
inputs = [input() for i in range(num_i)]


x = []
for _ in inputs:
    for value in _:
        x.append(value)
x = np.array(x)
x = x.reshape(num_i, num_j)

count = 0
boolean = True
while (boolean):
    count += 1
    i_arr = []
    j_arr = []
    for i in range(num_i):
        for j in range(num_j):
            if (x[i][j] == "#"):
                i_arr.append(i)
                j_arr.append(j)
    for i, j in zip(i_arr, j_arr):
        if (i == 0) & (j == 0):
            x[1][0] = "#"
            x[0][1] = "#"
        elif (i == num_i - 1) & (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i][j - 1] = "#"
        elif (i == num_i - 1) & (j == 0):
            x[i - 1][0] = "#"
            x[i][1] = "#"
        elif (i == 0) & (j == num_j - 1):
            x[1][j] = "#"
            x[0][j - 1] = "#"
        elif (i == 0):
            x[1][j] = "#"
            x[0][j - 1] = "#"
            x[0][j + 1] = "#"
        elif (j == 0):
            x[i - 1][0] = "#"
            x[i + 1][0] = "#"
            x[i][1] = "#"
        elif (i == num_i - 1):
            x[i - 1][j] = "#"
            x[i][j + 1] = "#"
            x[i][j - 1] = "#"
        elif (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
        else:
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
            x[i][j + 1] = "#"
    if len(set(list(x.flatten()))) == 1:
        print(count)
        boolean = False
    else:
        boolean = True

Fixed submission:
from collections import deque

H, W = map(int, input().split())

# input black cells
black_cells = []

for h in range(H):
    line = list(input())
    for w in range(W):
        if line[w] == "#":
            black_cells.append(h * W + w)


# Graph
def r(p):
    q_list = []
    h = p // W
    w = p % W
    if h != 0:
        q_list.append(p - W)
    if h != H-1:
        q_list.append(p + W)
    if w != 0:
        q_list.append(p - 1)
    if w != W-1:
        q_list.append(p + 1)
    return q_list


queue = deque(black_cells)
d = [10000] * (H * W)
for i in black_cells:
    d[i] = 0

# dijkstra
while len(queue) > 0:
    p = queue.popleft()
    for q in r(p):
        if d[q] > d[p] + 1:
            d[q] = d[p] + 1
            queue.append(q)

print(max(d))

Buggy python submission (verdict: Runtime Error):
import numpy as np

num_i, num_j = input().split(" ")
num_i = int(num_i)
num_j = int(num_j)
inputs = [input() for i in range(num_i)]

x = []
for _ in inputs:
    for value in _:
        x.append(value)
x = np.array(x)
x = x.reshape(num_i, num_j)

count = 0
boolean = True
while (boolean):
    count += 1
    i_arr = []
    j_arr = []
    for i in range(num_i):
        for j in range(num_j):
            if (x[i][j] == "#"):
                i_arr.append(i)
                j_arr.append(j)
    for i, j in zip(i_arr, j_arr):
        if (i == 0) & (j == 0):
            x[1][0] = "#"
            x[0][1] = "#"
        elif (i == num_i - 1) & (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i][j - 1] = "#"
        elif (i == num_i - 1) & (j == 0):
            x[i - 1][0] = "#"
            x[i][1] = "#"
        elif (i == 0) & (j == num_j - 1):
            x[1][j] = "#"
            x[0][j - 1] = "#"
        elif (i == 0):
            x[1][j] = "#"
            x[0][j - 1] = "#"
            x[0][j + 1] = "#"
        elif (j == 0):
            x[i - 1][0] = "#"
            x[i + 1][0] = "#"
            x[i][1] = "#"
        elif (i == num_i - 1):
            x[i - 1][j] = "#"
            x[i][j + 1] = "#"
            x[i][j - 1] = "#"
        elif (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
        else:
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
            x[i][j + 1] = "#"
    if len(set(list(x.flatten()))) == 1:
        return(count)
        boolean = False
    else:
        boolean = True

Fixed submission:
from collections import deque

H, W = map(int, input().split())

# input black cells
black_cells = []

for h in range(H):
    line = list(input())
    for w in range(W):
        if line[w] == "#":
            black_cells.append(h * W + w)


# Graph
def r(p):
    q_list = []
    h = p // W
    w = p % W
    if h != 0:
        q_list.append(p - W)
    if h != H-1:
        q_list.append(p + W)
    if w != 0:
        q_list.append(p - 1)
    if w != W-1:
        q_list.append(p + 1)
    return q_list


queue = deque(black_cells)
d = [10000] * (H * W)
for i in black_cells:
    d[i] = 0

# dijkstra
while len(queue) > 0:
    p = queue.popleft()
    for q in r(p):
        if d[q] > d[p] + 1:
            d[q] = d[p] + 1
            queue.append(q)

print(max(d))

Buggy python submission (verdict: Runtime Error):
import numpy as np

num_i, num_j = input().split()
num_i = int(num_i)
num_j = int(num_j)
inputs = [input() for i in range(num_i)]

x = []
for _ in inputs:
    for value in _:
        x.append(value)
x = np.array(x)
x = x.reshape(num_i, num_j)

count = 0
boolean = True
while (boolean):
    count += 1
    i_arr = []
    j_arr = []
    for i in range(num_i):
        for j in range(num_j):
            if (x[i][j] == "#"):
                i_arr.append(i)
                j_arr.append(j)
    for i, j in zip(i_arr, j_arr):
        if (i == 0) & (j == 0):
            x[1][0] = "#"
            x[0][1] = "#"
        elif (i == num_i - 1) & (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i][j - 1] = "#"
        elif (i == num_i - 1) & (j == 0):
            x[i - 1][0] = "#"
            x[i][1] = "#"
        elif (i == 0) & (j == num_j - 1):
            x[1][j] = "#"
            x[0][j - 1] = "#"
        elif (i == 0):
            x[1][j] = "#"
            x[0][j - 1] = "#"
            x[0][j + 1] = "#"
        elif (j == 0):
            x[i - 1][0] = "#"
            x[i + 1][0] = "#"
            x[i][1] = "#"
        elif (i == num_i - 1):
            x[i - 1][j] = "#"
            x[i][j + 1] = "#"
            x[i][j - 1] = "#"
        elif (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
        else:
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
            x[i][j + 1] = "#"
    if len(set(list(x.flatten()))) == 1:
        return(count)
        boolean = False
    else:
        boolean = True

Fixed submission:
from collections import deque

H, W = map(int, input().split())

# input black cells
black_cells = []

for h in range(H):
    line = list(input())
    for w in range(W):
        if line[w] == "#":
            black_cells.append(h * W + w)


# Graph
def r(p):
    q_list = []
    h = p // W
    w = p % W
    if h != 0:
        q_list.append(p - W)
    if h != H-1:
        q_list.append(p + W)
    if w != 0:
        q_list.append(p - 1)
    if w != W-1:
        q_list.append(p + 1)
    return q_list


queue = deque(black_cells)
d = [10000] * (H * W)
for i in black_cells:
    d[i] = 0

# dijkstra
while len(queue) > 0:
    p = queue.popleft()
    for q in r(p):
        if d[q] > d[p] + 1:
            d[q] = d[p] + 1
            queue.append(q)

print(max(d))

Buggy python submission (verdict: Runtime Error):
import numpy as np

num_i, num_j = input().split()
num_i = int(num_i)
num_j = int(num_j)
inputs = [input() for i in range(num_i)]

x = []
for _ in inputs:
    for value in _:
        x.append(value)
x = np.array(x)
x = x.reshape(num_i, num_j)

count = 0
boolean = True
while (boolean):
    count += 1
    i_arr = []
    j_arr = []
    for i in range(num_i):
        for j in range(num_j):
            if (x[i][j] == "#"):
                i_arr.append(i)
                j_arr.append(j)
    for i, j in zip(i_arr, j_arr):
        if (i == 0) & (j == 0):
            x[1][0] = "#"
            x[0][1] = "#"
        elif (i == num_i - 1) & (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i][j - 1] = "#"
        elif (i == num_i - 1) & (j == 0):
            x[i - 1][0] = "#"
            x[i][1] = "#"
        elif (i == 0) & (j == num_j - 1):
            x[1][j] = "#"
            x[0][j - 1] = "#"
        elif (i == 0):
            x[1][j] = "#"
            x[0][j - 1] = "#"
            x[0][j + 1] = "#"
        elif (j == 0):
            x[i - 1][0] = "#"
            x[i + 1][0] = "#"
            x[i][1] = "#"
        elif (i == num_i - 1):
            x[i - 1][j] = "#"
            x[i][j + 1] = "#"
            x[i][j - 1] = "#"
        elif (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
        else:
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
            x[i][j + 1] = "#"
    if len(set(list(x.flatten()))) == 1:
        return(count)
        boolean = False
    else:
        boolean = True

Fixed submission:
from collections import deque

H, W = map(int, input().split())

# input black cells
black_cells = []

for h in range(H):
    line = list(input())
    for w in range(W):
        if line[w] == "#":
            black_cells.append(h * W + w)


# Graph
def r(p):
    q_list = []
    h = p // W
    w = p % W
    if h != 0:
        q_list.append(p - W)
    if h != H-1:
        q_list.append(p + W)
    if w != 0:
        q_list.append(p - 1)
    if w != W-1:
        q_list.append(p + 1)
    return q_list


queue = deque(black_cells)
d = [10000] * (H * W)
for i in black_cells:
    d[i] = 0

# dijkstra
while len(queue) > 0:
    p = queue.popleft()
    for q in r(p):
        if d[q] > d[p] + 1:
            d[q] = d[p] + 1
            queue.append(q)

print(max(d))

Buggy python submission (verdict: Runtime Error):
import numpy as np

num_i, num_j = input().split()
num_i = int(num_i)
num_j = int(num_j)
inputs = [input() for i in range(num_i)]

x = []
for _ in inputs:
    for value in _:
        x.append(value)
x = np.array(x)
x = x.reshape(num_i, num_j)

count = 0
boolean = True
while (boolean):
    count += 1
    i_arr = []
    j_arr = []
    for i in range(num_i):
        for j in range(num_j):
            if (x[i][j] == "#"):
                i_arr.append(i)
                j_arr.append(j)
    for i, j in zip(i_arr, j_arr):
        if (i == 0) & (j == 0):
            x[1][0] = "#"
            x[0][1] = "#"
        elif (i == num_i - 1) & (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i][j - 1] = "#"
        elif (i == num_i - 1) & (j == 0):
            x[i - 1][0] = "#"
            x[i][1] = "#"
        elif (i == 0) & (j == num_j - 1):
            x[1][j] = "#"
            x[0][j - 1] = "#"
        elif (i == 0):
            x[1][j] = "#"
            x[0][j - 1] = "#"
            x[0][j + 1] = "#"
        elif (j == 0):
            x[i - 1][0] = "#"
            x[i + 1][0] = "#"
            x[i][1] = "#"
        elif (i == num_i - 1):
            x[i - 1][j] = "#"
            x[i][j + 1] = "#"
            x[i][j - 1] = "#"
        elif (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
        else:
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
            x[i][j + 1] = "#"
    if len(set(list(x.flatten()))) == 1:
        print(count)
        boolean = False
    else:
        boolean = True

Fixed submission:
from collections import deque

H, W = map(int, input().split())

# input black cells
black_cells = []

for h in range(H):
    line = list(input())
    for w in range(W):
        if line[w] == "#":
            black_cells.append(h * W + w)


# Graph
def r(p):
    q_list = []
    h = p // W
    w = p % W
    if h != 0:
        q_list.append(p - W)
    if h != H-1:
        q_list.append(p + W)
    if w != 0:
        q_list.append(p - 1)
    if w != W-1:
        q_list.append(p + 1)
    return q_list


queue = deque(black_cells)
d = [10000] * (H * W)
for i in black_cells:
    d[i] = 0

# dijkstra
while len(queue) > 0:
    p = queue.popleft()
    for q in r(p):
        if d[q] > d[p] + 1:
            d[q] = d[p] + 1
            queue.append(q)

print(max(d))

Buggy python submission (verdict: Runtime Error):
num_i, num_j = input().split()
num_i = int(num_i)
num_j = int(num_j)
inputs = [input() for i in range(num_i)]
x = []
for _ in inputs:
    for value in _:
        x.append(value)
x = np.array(x)
x = x.reshape(num_i, num_j)

count = 0
boolean = True
while (boolean):
    count += 1
    i_arr = []
    j_arr = []
    for i in range(num_i):
        for j in range(num_j):
            if (x[i][j] == "#"):
                i_arr.append(i)
                j_arr.append(j)
    for i, j in zip(i_arr, j_arr):
        if (i == 0) & (j == 0):
            x[1][0] = "#"
            x[0][1] = "#"
        elif (i == num_i - 1) & (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i][j - 1] = "#"
        elif (i == num_i - 1) & (j == 0):
            x[i - 1][0] = "#"
            x[i][1] = "#"
        elif (i == 0) & (j == num_j - 1):
            x[1][j] = "#"
            x[0][j - 1] = "#"
        elif (i == 0):
            x[1][j] = "#"
            x[0][j - 1] = "#"
            x[0][j + 1] = "#"
        elif (j == 0):
            x[i - 1][0] = "#"
            x[i + 1][0] = "#"
            x[i][1] = "#"
        elif (i == num_i - 1):
            x[i - 1][j] = "#"
            x[i][j + 1] = "#"
            x[i][j - 1] = "#"
        elif (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
        else:
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
            x[i][j + 1] = "#"
    if len(set(list(x.flatten()))) == 1:
        print(count)
        boolean = False
    else:
        boolean = True

Fixed submission:
from collections import deque

H, W = map(int, input().split())

# input black cells
black_cells = []

for h in range(H):
    line = list(input())
    for w in range(W):
        if line[w] == "#":
            black_cells.append(h * W + w)


# Graph
def r(p):
    q_list = []
    h = p // W
    w = p % W
    if h != 0:
        q_list.append(p - W)
    if h != H-1:
        q_list.append(p + W)
    if w != 0:
        q_list.append(p - 1)
    if w != W-1:
        q_list.append(p + 1)
    return q_list


queue = deque(black_cells)
d = [10000] * (H * W)
for i in black_cells:
    d[i] = 0

# dijkstra
while len(queue) > 0:
    p = queue.popleft()
    for q in r(p):
        if d[q] > d[p] + 1:
            d[q] = d[p] + 1
            queue.append(q)

print(max(d))

Buggy python submission (verdict: Runtime Error):
count = 0
boolean = True
while (boolean):
    count += 1
    i_arr = []
    j_arr = []
    for i in range(num_i):
        for j in range(num_j):
            if (x[i][j] == "#"):
                i_arr.append(i)
                j_arr.append(j)
    for i, j in zip(i_arr, j_arr):
        if (i == 0) & (j == 0):
            x[1][0] = "#"
            x[0][1] = "#"
        elif (i == num_i - 1) & (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i][j - 1] = "#"
        elif (i == num_i - 1) & (j == 0):
            x[i - 1][0] = "#"
            x[i][1] = "#"
        elif (i == 0) & (j == num_j - 1):
            x[1][j] = "#"
            x[0][j - 1] = "#"
        elif (i == 0):
            x[1][j] = "#"
            x[0][j - 1] = "#"
            x[0][j + 1] = "#"
        elif (j == 0):
            x[i - 1][0] = "#"
            x[i + 1][0] = "#"
            x[i][1] = "#"
        elif (i == num_i - 1):
            x[i - 1][j] = "#"
            x[i][j + 1] = "#"
            x[i][j - 1] = "#"
        elif (j == num_j - 1):
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
        else:
            x[i - 1][j] = "#"
            x[i + 1][j] = "#"
            x[i][j - 1] = "#"
            x[i][j + 1] = "#"
    if len(set(list(x.flatten()))) == 1:
        print(count)
        boolean = False
    else:
        boolean = True

Fixed submission:
from collections import deque

H, W = map(int, input().split())

# input black cells
black_cells = []

for h in range(H):
    line = list(input())
    for w in range(W):
        if line[w] == "#":
            black_cells.append(h * W + w)


# Graph
def r(p):
    q_list = []
    h = p // W
    w = p % W
    if h != 0:
        q_list.append(p - W)
    if h != H-1:
        q_list.append(p + W)
    if w != 0:
        q_list.append(p - 1)
    if w != W-1:
        q_list.append(p + 1)
    return q_list


queue = deque(black_cells)
d = [10000] * (H * W)
for i in black_cells:
    d[i] = 0

# dijkstra
while len(queue) > 0:
    p = queue.popleft()
    for q in r(p):
        if d[q] > d[p] + 1:
            d[q] = d[p] + 1
            queue.append(q)

print(max(d))