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

h, w = map(int, input().split())
cx, cy = map(lambda x: int(x) - 1, input().split())
dx, dy = map(lambda x: int(x) - 1, input().split())
s = [input() for _ in range(h)]
c = [[10**6] * w for _ in range(h)]


def bfs():
    d = ((1, 0), (-1, 0), (0, 1), (0, -1))
    q = deque([(cx, cy)])

    c[cx][cy] = 0

    while q:
        x, y = q.pop()
        cp = c[x][y]
        if (x, y) == (dx, dy):
            c[x][y] = cp
            break
        for i, j in d:
            nx = x + i
            ny = y + j
            if 0 <= nx < h and 0 <= ny < w and s[nx][ny] != "#" and c[nx][
                    ny] > cp:
                q.append((nx, ny))
                c[nx][ny] = cp
        cp += 1
        for i in range(-2, 3):
            for j in range(-2, 3):
                nx = x + i
                ny = y + j
                if 0 <= nx < h and 0 <= ny < w and s[nx][ny] != "#" and c[nx][
                        ny] > cp:
                    c[nx][ny] = cp
                    q.appendleft((nx, ny))

    return -1 * (c[dx][dy] == 10**6) or c[dx][dy]


print(bfs())


Fixed submission:
from collections import deque


h, w = map(int,input().split())
ch, cw = map(lambda x: int(x) - 1, input().split())
dh, dw = map(lambda x: int(x) - 1, input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch, cw)])
S = [[float("inf")]*w for _ in range(h)]
S[ch][cw] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = ((1,0),(0,1),(-1,0),(0,-1))
    ans = S[y][x]

    if (y, x) == (dh, dw):
            S[y][x] = ans
            break

    for j, i in dx_dy:
        if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
            queue.appendleft((y+j, x+i))
            S[y+j][x+i] = ans
            

    ans += 1
    for i in range(-2, 3):
        for j in range(-2, 3):
            if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
                S[y+j][x+i] = ans
                queue.append((y+j, x+i))


if S[dh][dw] == float("inf"):
    print(-1)
else:
    print(S[dh][dw])

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


h, w = map(int,input().split())
ch, cw = map(lambda x: int(x) - 1, input().split())
dh, dw = map(lambda x: int(x) - 1, input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch, cw)])
S = [[float("inf")]*w for _ in range(h)]
S[ch][cw] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = ((1,0),(0,1),(-1,0),(0,-1))
    ans = S[y][x]

    if (y, x) == (dh, dw):
            S[y][x] = ans
            break

    for j, i in dx_dy:
        if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
            queue.appendleft((y+j, x+i))
            S[y+j][x+i] = ans
            

    ans += 1
    for i in range(-2, 3):
        for j in range(-2, 3):
            if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
                S[y+j][x+i] = ans
                queue.append((y+j, x+i))


if S[dh][dw] == float("inf"):
    print(-1)
else:
    print(S[dh][dw])


Fixed submission:
from collections import deque


h, w = map(int,input().split())
ch, cw = map(lambda x: int(x) - 1, input().split())
dh, dw = map(lambda x: int(x) - 1, input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch, cw)])
S = [[float("inf")]*w for _ in range(h)]
S[ch][cw] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = ((1,0),(0,1),(-1,0),(0,-1))
    ans = S[y][x]

    if (y, x) == (dh, dw):
            S[y][x] = ans
            break

    for j, i in dx_dy:
        if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
            queue.appendleft((y+j, x+i))
            S[y+j][x+i] = ans
            

    ans += 1
    for i in range(-2, 3):
        for j in range(-2, 3):
            if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
                S[y+j][x+i] = ans
                queue.append((y+j, x+i))


if S[dh][dw] == float("inf"):
    print(-1)
else:
    print(S[dh][dw])

Buggy python submission (verdict: Runtime Error):
from collections import deque
import sys

sys.setrecursionlimit(10**9)

h, w = map(int,input().split())
ch, cw = map(lambda x: int(x) - 1, input().split())
dh, dw = map(lambda x: int(x) - 1, input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch-1, cw-1)])
S = [[float("inf")]*w for _ in range(h)]
S[ch][cw] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = ((1,0),(0,1),(-1,0),(0,-1))
    ans = S[y][x]

    if (y, x) == (dy, dx):
            S[y][x] = ans
            break

    for j, i in dx_dy:
        if 0 <= x+i < w and 0 <= y+j < h:
            if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == ".":
                S[y+j][x+i] = ans
                queue.appendleft((y+j, x+i))

    ans += 1
    for i in range(-2, 3):
        for j in range(-2, 3):
            if i != 0 and j != 0:
                if 0 <= x+i < w and 0 <= y+j < h:
                    if S[y+j][x+i] > ans and G[y+j][x+i] == ".":
                        S[y+j][x+i] = ans
                        queue.append((y+j, x+i))


if S[dh][dw] == float("inf"):
    print(-1)
else:
    print(S[dh][dw])


Fixed submission:
from collections import deque


h, w = map(int,input().split())
ch, cw = map(lambda x: int(x) - 1, input().split())
dh, dw = map(lambda x: int(x) - 1, input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch, cw)])
S = [[float("inf")]*w for _ in range(h)]
S[ch][cw] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = ((1,0),(0,1),(-1,0),(0,-1))
    ans = S[y][x]

    if (y, x) == (dh, dw):
            S[y][x] = ans
            break

    for j, i in dx_dy:
        if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
            queue.appendleft((y+j, x+i))
            S[y+j][x+i] = ans
            

    ans += 1
    for i in range(-2, 3):
        for j in range(-2, 3):
            if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
                S[y+j][x+i] = ans
                queue.append((y+j, x+i))


if S[dh][dw] == float("inf"):
    print(-1)
else:
    print(S[dh][dw])

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

sys.setrecursionlimit(10**9)

h, w = map(int,input().split())
ch, cw = map(int,input().split())
dh, dw = map(int,input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch-1, cw-1)])
S = [[float("inf")]*w for _ in range(h)]
S[ch-1][cw-1] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = [(1,0),(0,1),(-1,0),(0,-1)]
    for j, i in dx_dy:
        if 0 <= x+i < w and 0 <= y+j < h:
            if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == ".":
                S[y+j][x+i] = S[y][x]
                queue.appendleft((y+j, x+i))
    magic = ((-2, -2), (-2, -1), (-2, 0), (-2, 1), (-2, 2), (-1, -2), (-1, -1), (-1, 1), (-1, 2), (0, -2), (0, 2), (1, -2), (1, -1), (1, 1), (1, 2), (2, -2), (2, -1), (2, 0), (2, 1), (2, 2))
    for j, i in magic:
            if 0 <= x+i < w and 0 <= y+j < h:
                if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == ".":
                    S[y+j][x+i] = S[y][x] + 1
                    queue.append((y+j, x+i))


if S[dh-1][dw-1] == float("inf"):
    print(-1)
else:
    print(S[dh-1][dw-1])


Fixed submission:
from collections import deque


h, w = map(int,input().split())
ch, cw = map(lambda x: int(x) - 1, input().split())
dh, dw = map(lambda x: int(x) - 1, input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch, cw)])
S = [[float("inf")]*w for _ in range(h)]
S[ch][cw] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = ((1,0),(0,1),(-1,0),(0,-1))
    ans = S[y][x]

    if (y, x) == (dh, dw):
            S[y][x] = ans
            break

    for j, i in dx_dy:
        if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
            queue.appendleft((y+j, x+i))
            S[y+j][x+i] = ans
            

    ans += 1
    for i in range(-2, 3):
        for j in range(-2, 3):
            if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
                S[y+j][x+i] = ans
                queue.append((y+j, x+i))


if S[dh][dw] == float("inf"):
    print(-1)
else:
    print(S[dh][dw])

Buggy python submission (verdict: Runtime Error):
from collections import deque

h,w = map(int,input().split())
ch, cw = map(int,input().split())
dh, dw = map(int,input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch-1, cw-1)])
S = [[float("inf")]*w for _ in range(h)]
S[ch-1][cw-1] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = [[1,0],[0,1],[-1,0],[0,-1]]
    for k in range(4):
        i, j = dx_dy[i][0], dx_dy[i][1]
        if 0 <= x+i < w and 0 <= y+j < h:
            if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == ".":
                S[y+j][x+i] = S[y][x]
                queue.appendleft((y+j, x+i))

    for i in range(-2, 3):
        for j in range(-2, 3):
            if i != 0 and j != 0:
                if 0 <= x+i < w and 0 <= y+j < h:
                    if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == ".":
                        S[y+j][x+i] = S[y][x] + 1
                        queue.append((y+j, x+i))


if S[dh-1][dw-1] == float("inf"):
    print(-1)
else:
    print(S[dh-1][dw-1])

Fixed submission:
from collections import deque


h, w = map(int,input().split())
ch, cw = map(lambda x: int(x) - 1, input().split())
dh, dw = map(lambda x: int(x) - 1, input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch, cw)])
S = [[float("inf")]*w for _ in range(h)]
S[ch][cw] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = ((1,0),(0,1),(-1,0),(0,-1))
    ans = S[y][x]

    if (y, x) == (dh, dw):
            S[y][x] = ans
            break

    for j, i in dx_dy:
        if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
            queue.appendleft((y+j, x+i))
            S[y+j][x+i] = ans
            

    ans += 1
    for i in range(-2, 3):
        for j in range(-2, 3):
            if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
                S[y+j][x+i] = ans
                queue.append((y+j, x+i))


if S[dh][dw] == float("inf"):
    print(-1)
else:
    print(S[dh][dw])

Buggy python submission (verdict: Runtime Error):
from collections import deque

h,w = map(int,input().split())
ch, cw = map(int,input().split())
dh, dw = map(int,input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch-1, cw-1)])
S = [[float("inf")]*w for _ in range(h)]
S[ch-1][cw-1] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = [[1,0],[0,1],[-1,0],[0,-1]]
    for k in range(4):
        i, j = dx_dy[i][0], dx_dy[i][1]
        if 0 <= x+i < w and 0 <= y+j < h:
            if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == ".":
                S[y+j][x+i] = S[y][x]
                queue.appendleft((y+j, x+i))

    for i in range(-2, 3):
        for j in range(-2, 3):
            if i != 0 and j != 0:
                if 0 <= x+i < w and 0 <= y+j < h:
                    if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == ".":
                        S[y+j][x+i] = S[y][x] + 1
                        queue.append((y+j, x+i))


if S[dh-1][dw-1] == float("inf"):
    print(-1)
else:
    print(S[dh-1][dw-1])


Fixed submission:
from collections import deque


h, w = map(int,input().split())
ch, cw = map(lambda x: int(x) - 1, input().split())
dh, dw = map(lambda x: int(x) - 1, input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch, cw)])
S = [[float("inf")]*w for _ in range(h)]
S[ch][cw] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = ((1,0),(0,1),(-1,0),(0,-1))
    ans = S[y][x]

    if (y, x) == (dh, dw):
            S[y][x] = ans
            break

    for j, i in dx_dy:
        if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
            queue.appendleft((y+j, x+i))
            S[y+j][x+i] = ans
            

    ans += 1
    for i in range(-2, 3):
        for j in range(-2, 3):
            if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
                S[y+j][x+i] = ans
                queue.append((y+j, x+i))


if S[dh][dw] == float("inf"):
    print(-1)
else:
    print(S[dh][dw])

Buggy python submission (verdict: Runtime Error):
from collections import deque

h,w = map(int,input().split())
ch, cw = map(int,input().split())
dh, dw = map(int,input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([ch-1, cw-1])
S = [[float("inf")]*w for _ in range(h)]
S[ch-1][cw-1] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = [[1,0],[0,1],[-1,0],[0,-1]]
    for k in range(4):
        i, j = k[0], k[1]
        if 0 <= x+i < w and 0 <= y+j < h:
            if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == ".":
                S[y+j][x+i] = S[y][x]
                queue.appendleft((y+j, x+i))

    for i in range(-2, 3):
        for j in range(-2, 3):
            if i != 0 and j != 0:
                if 0 <= x+i < w and 0 <= y+j < h:
                    if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == ".":
                        S[y+j][x+i] = S[y][x] + 1
                        queue.append((y+j, x+i))


if S[dh+1][dw+1] == float("inf"):
    print(-1)
else:
    print(S[dh-1][dw-1])


Fixed submission:
from collections import deque


h, w = map(int,input().split())
ch, cw = map(lambda x: int(x) - 1, input().split())
dh, dw = map(lambda x: int(x) - 1, input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch, cw)])
S = [[float("inf")]*w for _ in range(h)]
S[ch][cw] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = ((1,0),(0,1),(-1,0),(0,-1))
    ans = S[y][x]

    if (y, x) == (dh, dw):
            S[y][x] = ans
            break

    for j, i in dx_dy:
        if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
            queue.appendleft((y+j, x+i))
            S[y+j][x+i] = ans
            

    ans += 1
    for i in range(-2, 3):
        for j in range(-2, 3):
            if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
                S[y+j][x+i] = ans
                queue.append((y+j, x+i))


if S[dh][dw] == float("inf"):
    print(-1)
else:
    print(S[dh][dw])

Buggy python submission (verdict: Runtime Error):
from collections import deque

h,w = map(int,input().split())
ch, cw = map(int,input().split())
dh, dw = map(int,input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([ch-1, cw-1])
S = [[float("inf")]*w for _ in range(h)]
S[ch-1][cw-1] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = [[1,0],[0,1],[-1,0],[0,-1]]
    for k in range(4):
        i, j = k[0], k-1 
        if 0 <= x+i < h and 0 <= y < w:
            if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == ".":
                S[y+j][x+i] = S[y][x]
                queue.appendleft((y+j, x+i))

    for i in range(-2, 3):
        for j in range(-2, 3):
            if i != 0 and j != 0:
                if 0 <= x+i < h and 0 <= y < w:
                    if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == ".":
                        S[y+j][x+i] = S[y][x] + 1
                        queue.append((y+j, x+i))


if S[dh+1][dw+1] == float("inf"):
    print(-1)
else:
    print(S[dh-1][dw-1])


Fixed submission:
from collections import deque


h, w = map(int,input().split())
ch, cw = map(lambda x: int(x) - 1, input().split())
dh, dw = map(lambda x: int(x) - 1, input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch, cw)])
S = [[float("inf")]*w for _ in range(h)]
S[ch][cw] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = ((1,0),(0,1),(-1,0),(0,-1))
    ans = S[y][x]

    if (y, x) == (dh, dw):
            S[y][x] = ans
            break

    for j, i in dx_dy:
        if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
            queue.appendleft((y+j, x+i))
            S[y+j][x+i] = ans
            

    ans += 1
    for i in range(-2, 3):
        for j in range(-2, 3):
            if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
                S[y+j][x+i] = ans
                queue.append((y+j, x+i))


if S[dh][dw] == float("inf"):
    print(-1)
else:
    print(S[dh][dw])

Buggy python submission (verdict: Runtime Error):
from collections import deque

h,w = map(int,input().split())
ch, cw = map(int,input().split())
dh, dw = map(int,input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([ch-1, cw-1])
S = [[float("inf")]*w for _ in range(h)]
S[ch-1][cw-1] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = [[1,0],[0,1],[-1,0],[0,-1]]
    for i, j in dx_dy:
        if 0 <= x+i < h and 0 <= y < w:
            if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == ".":
                S[y+j][x+i] = S[y][x]
                queue.appendleft((y+j, x+i))

    for i in range(-2, 3):
        for j in range(-2, 3):
            if i != 0 and j != 0:
                if 0 <= x+i < h and 0 <= y < w:
                    if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == "."::
                        S[y+j][x+i] = S[y][x] + 1
                        queue.append((y+j, x+i))


if S[dh+1][dw+1] == float("inf"):
    print(-1)
else:
    print(S[dh-1][dw-1])


Fixed submission:
from collections import deque


h, w = map(int,input().split())
ch, cw = map(lambda x: int(x) - 1, input().split())
dh, dw = map(lambda x: int(x) - 1, input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch, cw)])
S = [[float("inf")]*w for _ in range(h)]
S[ch][cw] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = ((1,0),(0,1),(-1,0),(0,-1))
    ans = S[y][x]

    if (y, x) == (dh, dw):
            S[y][x] = ans
            break

    for j, i in dx_dy:
        if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
            queue.appendleft((y+j, x+i))
            S[y+j][x+i] = ans
            

    ans += 1
    for i in range(-2, 3):
        for j in range(-2, 3):
            if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
                S[y+j][x+i] = ans
                queue.append((y+j, x+i))


if S[dh][dw] == float("inf"):
    print(-1)
else:
    print(S[dh][dw])

Buggy python submission (verdict: Runtime Error):
from collections import deque

h,w = map(int,input().split())
ch, cw = map(int,input().split())
dh, dw = map(int,input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([ch-1, cw-1])
S = [[float("inf")]*w for _ in range(h)]
S[ch-1][cw-1] = 0

while queue:
    y, x = queue.popleft()
    for i in range(-1, 2):
        for j in range(-1, 2):
            if i != 0 and j != 0:
                if 0 <= x+i < h and 0 <= y < w:
                    if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == ".":
                        S[y+j][x+i] = S[y][x]
                        queue.appendleft((y+j, x+i))

    for i in range(-2, 3):
        for j in range(-2, 3):
            if i != 0 and j != 0:
                if 0 <= x+i < h and 0 <= y < w:
                    if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == ".":
                        S[y+j][x+i] = S[y][x] + 1
                        queue.appendleft((y+j, x+i))


if S[dh+1][dw+1] == float("inf"):
    print(-1)
else:
    print(S[dh-1][dw-1])


Fixed submission:
from collections import deque


h, w = map(int,input().split())
ch, cw = map(lambda x: int(x) - 1, input().split())
dh, dw = map(lambda x: int(x) - 1, input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch, cw)])
S = [[float("inf")]*w for _ in range(h)]
S[ch][cw] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = ((1,0),(0,1),(-1,0),(0,-1))
    ans = S[y][x]

    if (y, x) == (dh, dw):
            S[y][x] = ans
            break

    for j, i in dx_dy:
        if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
            queue.appendleft((y+j, x+i))
            S[y+j][x+i] = ans
            

    ans += 1
    for i in range(-2, 3):
        for j in range(-2, 3):
            if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
                S[y+j][x+i] = ans
                queue.append((y+j, x+i))


if S[dh][dw] == float("inf"):
    print(-1)
else:
    print(S[dh][dw])

Buggy python submission (verdict: Runtime Error):
from collections import deque

h,w = map(int,input().split())
ch, cw = map(int,input().split())
dh, dw = map(int,input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([ch-1, cw-1])
S = [[float("inf")]*w for _ in range(h)]
S[ch-1][cw-1] = 0

while queue:
    y, x = queue.popleft()
    for i in range(-1, 2):
        for j in range(-1, 2):
            if i != 0 and j != 0:
                if 0 <= x+i < h and 0 <= y < w:
                    if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == ".":
                        S[y+j][x+i] = S[y][x]
                        queue.appendleft((y+j, x+i))

    for i in range(-2, 3):
        for j in range(-2, 3):
            if i != 0 and j != 0:
                if 0 <= x+i < h and 0 <= y < w:
                    if S[y+j][x+i] > S[y][x] and G[y+j][x+i] == "."::
                        S[y+j][x+i] = S[y][x] + 1
                        queue.appendleft((y+j, x+i))


if S[dh+1][dw+1] == float("inf"):
    print(-1)
else:
    print(S[dh-1][dw-1])


Fixed submission:
from collections import deque


h, w = map(int,input().split())
ch, cw = map(lambda x: int(x) - 1, input().split())
dh, dw = map(lambda x: int(x) - 1, input().split())

G = []
for i in range(h):
    G.append(list(input()))

queue = deque([(ch, cw)])
S = [[float("inf")]*w for _ in range(h)]
S[ch][cw] = 0

while queue:
    y, x = queue.popleft()
    dx_dy = ((1,0),(0,1),(-1,0),(0,-1))
    ans = S[y][x]

    if (y, x) == (dh, dw):
            S[y][x] = ans
            break

    for j, i in dx_dy:
        if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
            queue.appendleft((y+j, x+i))
            S[y+j][x+i] = ans
            

    ans += 1
    for i in range(-2, 3):
        for j in range(-2, 3):
            if 0 <= x+i < w and 0 <= y+j < h and S[y+j][x+i] > ans and G[y+j][x+i] == ".":
                S[y+j][x+i] = ans
                queue.append((y+j, x+i))


if S[dh][dw] == float("inf"):
    print(-1)
else:
    print(S[dh][dw])