Buggy python submission (verdict: Runtime Error):
from collections import deque
H,W = list(map(int,input().split()))
start = list(map(lambda x:int(x)-1,input().split()))
goal = list(map(lambda x:int(x)-1,input().split()))
A = [input() for _ in range(H)]
visited = [[0]*W for _ in range(H)]
B = deque([[start[0],start[1],0]])
warp = []
for i in range(-2,3):
    for j in range(-2,3):
            warp.append([i,j])

num = 0
# print(start,warp)
while 1:
    y,x,n = B.popleft()
    if visited[y][x] == 1:continue
    if [y,x] == goal:
        num = n
        break
    visited[y][x] = 1
    for dy,dx in [[1,0],[0,1],[-1,0],[0,-1]]:
        if (y+dy<0)|(x+dx<0)|(y+dy>=H)|(x+dx>=W):continue
        if (A[y+dy][x+dx]==".")&(visited[y+dy][x+dx]==0):
            B.appendleft([y+dy,x+dx,n])
    for dy,dx in warp:
        if (y+dy<0)|(x+dx<0)|(y+dy>=H)|(x+dx>=W):continue
        if (A[y+dy][x+dx]==".")&(visited[y+dy][x+dx]==0):
            B.append([y+dy,x+dx,n+1])
    if not B:
        num = -1
        break

print(num)

Fixed submission:
from collections import deque
H,W = list(map(int,input().split()))
start = list(map(lambda x:int(x)-1,input().split()))
goal = list(map(lambda x:int(x)-1,input().split()))
A = [input() for _ in range(H)]
visited = [[0]*W for _ in range(H)]
B = deque([[start[0],start[1],0]])
warp = []
for i in range(-2,3):
    for j in range(-2,3):
            warp.append([i,j])

num = -1

while B:
    y,x,n = B.popleft()
    if visited[y][x] == 1:continue
    if [y,x] == goal:
        num = n
        break
    visited[y][x] = 1
    for dy,dx in [[1,0],[0,1],[-1,0],[0,-1]]:
        if (y+dy<0)|(x+dx<0)|(y+dy>=H)|(x+dx>=W):continue
        if (A[y+dy][x+dx]==".")&(visited[y+dy][x+dx]==0):
            B.appendleft([y+dy,x+dx,n])
    for dy,dx in warp:
        if (y+dy<0)|(x+dx<0)|(y+dy>=H)|(x+dx>=W):continue
        if (A[y+dy][x+dx]==".")&(visited[y+dy][x+dx]==0):
            B.append([y+dy,x+dx,n+1])

print(num)

Buggy python submission (verdict: Runtime Error):
from collections import deque
H,W = list(map(int,input().split()))
start = list(map(lambda x:int(x)-1,input().split()))
goal = list(map(lambda x:int(x)-1,input().split()))
A = [input() for _ in range(H)]
visited = [[0]*W for _ in range(H)]
B = deque([[start[0],start[1],0]])
warp = []
for i in range(-2,3):
    for j in range(-2,3):
            warp.append([i,j])

num = 0
# print(start,warp)
while 1:
    y,x,n = B.popleft()
    if visited[y][x] == 1:continue
    if [y,x] == goal:
        num = n
        break
    visited[y][x] = 1
    for dy,dx in [[1,0],[0,1],[-1,0],[0,-1]]:
        if (y+dy<0)|(x+dx<0)|(y+dy>=H)|(x+dx>=W):continue
        if (A[y+dy][x+dx]==".")&(visited[y+dy][x+dx]==0):
            B.appendleft([y+dy,x+dx,n])
    for dy,dx in warp:
        if (y+dy<0)|(x+dx<0)|(y+dy>=H)|(x+dx>=W):continue
        if (A[y+dy][x+dx]==".")&(visited[y+dy][x+dx]==0):
            B.append([y+dy,x+dx,n+1])
    if not B:
        num = -1
        break

print(num)

Fixed submission:
from collections import deque
H,W = list(map(int,input().split()))
start = list(map(lambda x:int(x)-1,input().split()))
goal = list(map(lambda x:int(x)-1,input().split()))
A = [input() for _ in range(H)]
visited = [[0]*W for _ in range(H)]
B = deque([[start[0],start[1],0]])
warp = []
for i in range(-2,3):
    for j in range(-2,3):
            warp.append([i,j])

num = -1

while B:
    y,x,n = B.popleft()
    if visited[y][x] == 1:continue
    if [y,x] == goal:
        num = n
        break
    visited[y][x] = 1
    for dy,dx in [[1,0],[0,1],[-1,0],[0,-1]]:
        if (y+dy<0)|(x+dx<0)|(y+dy>=H)|(x+dx>=W):continue
        if (A[y+dy][x+dx]==".")&(visited[y+dy][x+dx]==0):
            B.appendleft([y+dy,x+dx,n])
    for dy,dx in warp:
        if (y+dy<0)|(x+dx<0)|(y+dy>=H)|(x+dx>=W):continue
        if (A[y+dy][x+dx]==".")&(visited[y+dy][x+dx]==0):
            B.append([y+dy,x+dx,n+1])

print(num)