Buggy python submission (verdict: Time Limit Exceeded):
from collections import deque

h, w = map(int, input().split())
sy, sx = map(int, input().split())
gy, gx = map(int, input().split())
map = []
move = [[0, 1], [1, 0], [0, -1], [-1, 0]]
visit = [[-1]*w for i in range(h)]
visit[sy - 1][sx - 1] = 0
warp = []
cnt = 0

for i in range(-2, 3):
    for j in range(-2, 3):
        if i == 0 and j == 0:
            continue
        else:
            warp.append([i, j])

for i in range(h):
    s = input()
    map.append(s)

route = deque([[sy - 1, sx - 1]])
wroute = deque()

while route:
    while route:
        y, x = route.popleft()
        wroute.append([y, x])
        for i, j in move:
            k = y + i
            l = x + j
            if 0 <= k < h and 0 <= l < w:
                if map[k][l] == ".":
                    if visit[k][l] == visit[y][x]:
                        continue
                    visit[k][l] = visit[y][x]
                    route.append([k, l])
    while wroute:
        y, x = wroute.popleft()
        for i, j in warp:
            k = y + i
            l = x + j
            if 0 <= k < h and 0 <= l < w:
                if map[k][l] == ".":
                    if visit[k][l] != -1:
                        continue
                    visit[k][l] = visit[y][x] + 1
                    route.append([k, l])
    cnt += 1

print(visit[gy - 1][gx - 1])

Fixed submission:
from collections import deque

h, w = map(int, input().split())
sy, sx = map(int, input().split())
gy, gx = map(int, input().split())
map = []
move = [[0, 1], [1, 0], [0, -1], [-1, 0]]
visit = [[-1]*w for i in range(h)]
visit[sy - 1][sx - 1] = 0
warp = []
cnt = 0

for i in range(-2, 3):
    for j in range(-2, 3):
        if i == 0 and j == 0:
            continue
        else:
            warp.append([i, j])

for i in range(h):
    s = input()
    map.append(s)

route = deque([[sy - 1, sx - 1]])
wroute = deque()

while route:
    while route:
        y, x = route.popleft()
        wroute.append([y, x])
        for i, j in move:
            k = y + i
            l = x + j
            if 0 <= k < h and 0 <= l < w:
                if map[k][l] == ".":
                    if visit[k][l] == visit[y][x]:
                        continue
                    visit[k][l] = visit[y][x]
                    route.append([k, l])
    while wroute:
        y, x = wroute.popleft()
        for i, j in warp:
            k = y + i
            l = x + j
            if 0 <= k < h and 0 <= l < w:
                if map[k][l] == ".":
                    if visit[k][l] != -1:
                        continue
                    visit[k][l] = visit[y][x] + 1
                    route.append([k, l])
    cnt += 1

print(visit[gy - 1][gx - 1])

Buggy python submission (verdict: Time Limit Exceeded):
from collections import deque

h, w = map(int, input().split())
sy, sx = map(int, input().split())
gy, gx = map(int, input().split())
map = []
move = [[0, 1], [1, 0], [0, -1], [-1, 0]]
visit = [[-1]*w for i in range(h)]
visit[sy - 1][sx - 1] = 0
warp = []
cnt = 0

for i in range(-2, 3):
    for j in range(-2, 3):
        if i == 0 and j == 0:
            continue
        else:
            warp.append([i, j])

for i in range(h):
    s = input()
    map.append(s)

route = deque([[sy - 1, sx - 1]])

while route:
    while route:
        y, x = route.popleft()
        for i, j in move:
            k = y + i
            l = x + j
            if 0 <= k < h and 0 <= l < w:
                if map[k][l] == ".":
                    if visit[k][l] == visit[y][x]:
                        continue
                    visit[k][l] = visit[y][x]
                    route.append([k, l])
    wroute = deque([])
    for i in range(w):
        for j in range(h):
            if visit[j][i] == cnt:
                wroute.append([j, i])
    while wroute:
        y, x = wroute.popleft()
        for i, j in warp:
            k = y + i
            l = x + j
            if 0 <= k < h and 0 <= l < w:
                if map[k][l] == ".":
                    if visit[k][l] != -1:
                        continue
                    visit[k][l] = visit[y][x] + 1
                    route.append([k, l])
    cnt += 1

print(visit[gy - 1][gx - 1])

Fixed submission:
from collections import deque

h, w = map(int, input().split())
sy, sx = map(int, input().split())
gy, gx = map(int, input().split())
map = []
move = [[0, 1], [1, 0], [0, -1], [-1, 0]]
visit = [[-1]*w for i in range(h)]
visit[sy - 1][sx - 1] = 0
warp = []
cnt = 0

for i in range(-2, 3):
    for j in range(-2, 3):
        if i == 0 and j == 0:
            continue
        else:
            warp.append([i, j])

for i in range(h):
    s = input()
    map.append(s)

route = deque([[sy - 1, sx - 1]])
wroute = deque()

while route:
    while route:
        y, x = route.popleft()
        wroute.append([y, x])
        for i, j in move:
            k = y + i
            l = x + j
            if 0 <= k < h and 0 <= l < w:
                if map[k][l] == ".":
                    if visit[k][l] == visit[y][x]:
                        continue
                    visit[k][l] = visit[y][x]
                    route.append([k, l])
    while wroute:
        y, x = wroute.popleft()
        for i, j in warp:
            k = y + i
            l = x + j
            if 0 <= k < h and 0 <= l < w:
                if map[k][l] == ".":
                    if visit[k][l] != -1:
                        continue
                    visit[k][l] = visit[y][x] + 1
                    route.append([k, l])
    cnt += 1

print(visit[gy - 1][gx - 1])

Buggy python submission (verdict: Time Limit Exceeded):
from collections import deque

h, w = map(int, input().split())
sy, sx = map(int, input().split())
gy, gx = map(int, input().split())
map = []
move = [[0, 1], [1, 0], [0, -1], [-1, 0]]
visit = [[-1]*w for i in range(h)]
visit[sy - 1][sx - 1] = 0
warp = []
cnt = 0

for i in range(-2, 3):
    for j in range(-2, 3):
        warp.append([i, j])

for i in range(h):
    s = input()
    map.append(s)

route = deque([[sy - 1, sx - 1]])

while route:
    while route:
        y, x = route.popleft()
        for i, j in move:
            k = y + i
            l = x + j
            if 0 <= k < h and 0 <= l < w:
                if map[k][l] == ".":
                    if visit[k][l] == visit[y][x]:
                        continue
                    visit[k][l] = visit[y][x]
                    route.append([k, l])
    wroute = deque([])
    for i in range(w):
        for j in range(h):
            if visit[j][i] == cnt:
                wroute.append([j, i])
    wlist = []
    while wroute:
        y, x = wroute.popleft()
        for i, j in warp:
            k = y + i
            l = x + j
            if [k, l] not in wlist:
                wlist.append([k, l])
    
    for k, l in wlist:
        if 0 <= k < h and 0 <= l < w:
            if map[k][l] == ".":
                if visit[k][l] != -1:
                    continue
                visit[k][l] = visit[y][x] + 1
                route.append([k, l])
    cnt += 1

print(visit[gy - 1][gx - 1])

Fixed submission:
from collections import deque

h, w = map(int, input().split())
sy, sx = map(int, input().split())
gy, gx = map(int, input().split())
map = []
move = [[0, 1], [1, 0], [0, -1], [-1, 0]]
visit = [[-1]*w for i in range(h)]
visit[sy - 1][sx - 1] = 0
warp = []
cnt = 0

for i in range(-2, 3):
    for j in range(-2, 3):
        if i == 0 and j == 0:
            continue
        else:
            warp.append([i, j])

for i in range(h):
    s = input()
    map.append(s)

route = deque([[sy - 1, sx - 1]])
wroute = deque()

while route:
    while route:
        y, x = route.popleft()
        wroute.append([y, x])
        for i, j in move:
            k = y + i
            l = x + j
            if 0 <= k < h and 0 <= l < w:
                if map[k][l] == ".":
                    if visit[k][l] == visit[y][x]:
                        continue
                    visit[k][l] = visit[y][x]
                    route.append([k, l])
    while wroute:
        y, x = wroute.popleft()
        for i, j in warp:
            k = y + i
            l = x + j
            if 0 <= k < h and 0 <= l < w:
                if map[k][l] == ".":
                    if visit[k][l] != -1:
                        continue
                    visit[k][l] = visit[y][x] + 1
                    route.append([k, l])
    cnt += 1

print(visit[gy - 1][gx - 1])

Buggy python submission (verdict: Time Limit Exceeded):
from collections import deque

h, w = map(int, input().split())
sy, sx = map(int, input().split())
gy, gx = map(int, input().split())
map = []
move = [[0, 1], [1, 0], [0, -1], [-1, 0]]
visit = [[-1]*w for i in range(h)]
visit[sy - 1][sx - 1] = 0
warp = []
cnt = 0

for i in range(-2, 3):
    for j in range(-2, 3):
        warp.append([i, j])

for i in range(h):
    s = input()
    map.append(s)

route = deque([[sy - 1, sx - 1]])

while route:
    while route:
        y, x = route.popleft()
        for i, j in move:
            k = y + i
            l = x + j
            if 0 <= k < h and 0 <= l < w:
                if map[k][l] == ".":
                    if visit[k][l] == visit[y][x]:
                        continue
                    visit[k][l] = visit[y][x]
                    route.append([k, l])
    wroute = deque([])
    for i in range(w):
        for j in range(h):
            if visit[j][i] == cnt:
                wroute.append([j, i])
    while wroute:
        y, x = wroute.popleft()
        for i, j in warp:
            k = y + i
            l = x + j
            if 0 <= k < h and 0 <= l < w:
                if map[k][l] == ".":
                    if visit[k][l] != -1:
                        continue
                    visit[k][l] = visit[y][x] + 1
                    route.append([k, l])
    cnt += 1

print(visit[gy - 1][gx - 1])

Fixed submission:
from collections import deque

h, w = map(int, input().split())
sy, sx = map(int, input().split())
gy, gx = map(int, input().split())
map = []
move = [[0, 1], [1, 0], [0, -1], [-1, 0]]
visit = [[-1]*w for i in range(h)]
visit[sy - 1][sx - 1] = 0
warp = []
cnt = 0

for i in range(-2, 3):
    for j in range(-2, 3):
        if i == 0 and j == 0:
            continue
        else:
            warp.append([i, j])

for i in range(h):
    s = input()
    map.append(s)

route = deque([[sy - 1, sx - 1]])
wroute = deque()

while route:
    while route:
        y, x = route.popleft()
        wroute.append([y, x])
        for i, j in move:
            k = y + i
            l = x + j
            if 0 <= k < h and 0 <= l < w:
                if map[k][l] == ".":
                    if visit[k][l] == visit[y][x]:
                        continue
                    visit[k][l] = visit[y][x]
                    route.append([k, l])
    while wroute:
        y, x = wroute.popleft()
        for i, j in warp:
            k = y + i
            l = x + j
            if 0 <= k < h and 0 <= l < w:
                if map[k][l] == ".":
                    if visit[k][l] != -1:
                        continue
                    visit[k][l] = visit[y][x] + 1
                    route.append([k, l])
    cnt += 1

print(visit[gy - 1][gx - 1])