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

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

c = [[] for i in range(h)]

for i in range(h):
    c[i] = input()
    
d = [[10000000 for i in range(w)] for j in range(h)]
    
d[ch-1][cw-1] = 0
que = deque([[ch-1,cw-1]])

dx = [1,0,-1,0]
dy = [0,1,0,-1]
ddx = [1,1,-1,-1,2,2,2,2,2,1,1,0,0,-1,-1,-2,-2,-2,-2,-2]
ddy = [1,-1,1,-1,2,1,0,-1,-2,2,-2,2,-2,2,-2,2,1,0,-1,-2]
    
while que:
    y,x = que.popleft()
        
    for k in range(4):
        nx = x + dx[k]
        ny = y + dy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[ny][nx] != '#':
            if d[ny][nx] > d[y][x]:
                d[ny][nx] = d[y][x]
                que.append([ny,nx])
                
    for k in range(20):
        nx = x + ddx[k]
        ny = y + ddy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[ny][nx] != '#':
            if d[ny][nx] > d[y][x] + 1:
                d[ny][nx] = d[y][x] + 1
                que.appendleft([ny,nx])

                
if d[dh-1][dw-1] == 10000000:
    print(-1)
else:
    print(d[dh-1][dw-1])

Fixed submission:
from collections import deque

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

c = [[] for i in range(h)]

for i in range(h):
    c[i] = input()
    
d = [[10000000 for i in range(w)] for j in range(h)]
    
d[ch-1][cw-1] = 0
que = deque([[ch-1,cw-1]])

dx = [1,0,-1,0]
dy = [0,1,0,-1]
ddx = [1,1,-1,-1,2,2,2,2,2,1,1,0,0,-1,-1,-2,-2,-2,-2,-2]
ddy = [1,-1,1,-1,2,1,0,-1,-2,2,-2,2,-2,2,-2,2,1,0,-1,-2]
    
while que:
    y,x = que.popleft()
        
    for k in range(4):
        nx = x + dx[k]
        ny = y + dy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[ny][nx] != '#':
            if d[ny][nx] > d[y][x]:
                d[ny][nx] = d[y][x]
                que.appendleft([ny,nx])
                
    for k in range(20):
        nx = x + ddx[k]
        ny = y + ddy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[ny][nx] != '#':
            if d[ny][nx] > d[y][x] + 1:
                d[ny][nx] = d[y][x] + 1
                que.append([ny,nx])

                
if d[dh-1][dw-1] == 10000000:
    print(-1)
else:
    print(d[dh-1][dw-1])

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

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

c = [[] for i in range(h)]

for i in range(h):
    c[i] = input()
    
d = [[10000000 for i in range(w)] for j in range(h)]
    
d[ch-1][cw-1] = 0
que = deque([[ch-1,cw-1]])

dx = [1,0,-1,0]
dy = [0,1,0,-1]
ddx = [1,1,-1,-1,2,2,2,2,2,1,1,0,0,-1,-1,-2,-2,-2,-2,-2]
ddy = [1,-1,1,-1,2,1,0,-1,-2,2,-2,2,-2,2,-2,2,1,0,-1,-2]
    
while que:
    y,x = que.popleft()
        
    for k in range(4):
        nx = x + dx[k]
        ny = y + dy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[ny][nx] != '#':
            if d[ny][nx] > d[y][x]:
                d[ny][nx] = d[y][x]
                que.append([ny,nx])
                
    for k in range(20):
        nx = x + ddx[k]
        ny = y + ddy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[ny][nx] != '#':
            if d[ny][nx] > d[y][x] + 1:
                d[ny][nx] = d[y][x] + 1
                que.append([ny,nx])

                
if d[dh-1][dw-1] == 10000000:
    print(-1)
else:
    print(d[dh-1][dw-1])

Fixed submission:
from collections import deque

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

c = [[] for i in range(h)]

for i in range(h):
    c[i] = input()
    
d = [[10000000 for i in range(w)] for j in range(h)]
    
d[ch-1][cw-1] = 0
que = deque([[ch-1,cw-1]])

dx = [1,0,-1,0]
dy = [0,1,0,-1]
ddx = [1,1,-1,-1,2,2,2,2,2,1,1,0,0,-1,-1,-2,-2,-2,-2,-2]
ddy = [1,-1,1,-1,2,1,0,-1,-2,2,-2,2,-2,2,-2,2,1,0,-1,-2]
    
while que:
    y,x = que.popleft()
        
    for k in range(4):
        nx = x + dx[k]
        ny = y + dy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[ny][nx] != '#':
            if d[ny][nx] > d[y][x]:
                d[ny][nx] = d[y][x]
                que.appendleft([ny,nx])
                
    for k in range(20):
        nx = x + ddx[k]
        ny = y + ddy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[ny][nx] != '#':
            if d[ny][nx] > d[y][x] + 1:
                d[ny][nx] = d[y][x] + 1
                que.append([ny,nx])

                
if d[dh-1][dw-1] == 10000000:
    print(-1)
else:
    print(d[dh-1][dw-1])

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

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

c = [[] for i in range(h)]

for i in range(h):
    c[i] = input()
    
d = [[10000000 for i in range(w)] for j in range(h)]
    
d[ch-1][cw-1] = 0
que = deque([[ch-1,cw-1]])

dx = [1,0,-1,0]
dy = [0,1,0,-1]
ddx = [1,1,-1,-1,2,2,2,2,2,1,1,0,0,-1,-1,-2,-2,-2,-2,-2]
ddy = [1,-1,1,-1,2,1,0,-1,-2,2,-2,2,-2,2,-2,2,1,0,-1,-2]
    
while que:
    y,x = que.popleft()
        
    for k in range(4):
        nx = x + dx[k]
        ny = y + dy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[y][x] != '#':
            if d[ny][nx] > d[y][x]:
                d[ny][nx] = d[y][x]
                que.append([ny,nx])
                
    for k in range(20):
        nx = x + ddx[k]
        ny = y + ddy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[y][x] != '#':
            if d[ny][nx] > d[y][x] + 1:
                d[ny][nx] = d[y][x] + 1
                que.append([ny,nx])

                
if d[dh-1][dw-1] == 10000000:
    print(-1)
else:
    print(d[dh-1][dw-1])

Fixed submission:
from collections import deque

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

c = [[] for i in range(h)]

for i in range(h):
    c[i] = input()
    
d = [[10000000 for i in range(w)] for j in range(h)]
    
d[ch-1][cw-1] = 0
que = deque([[ch-1,cw-1]])

dx = [1,0,-1,0]
dy = [0,1,0,-1]
ddx = [1,1,-1,-1,2,2,2,2,2,1,1,0,0,-1,-1,-2,-2,-2,-2,-2]
ddy = [1,-1,1,-1,2,1,0,-1,-2,2,-2,2,-2,2,-2,2,1,0,-1,-2]
    
while que:
    y,x = que.popleft()
        
    for k in range(4):
        nx = x + dx[k]
        ny = y + dy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[ny][nx] != '#':
            if d[ny][nx] > d[y][x]:
                d[ny][nx] = d[y][x]
                que.appendleft([ny,nx])
                
    for k in range(20):
        nx = x + ddx[k]
        ny = y + ddy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[ny][nx] != '#':
            if d[ny][nx] > d[y][x] + 1:
                d[ny][nx] = d[y][x] + 1
                que.append([ny,nx])

                
if d[dh-1][dw-1] == 10000000:
    print(-1)
else:
    print(d[dh-1][dw-1])

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

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

c = [[] for i in range(h)]

for i in range(h):
    c[i] = input()
    
d = [[10000000 for i in range(w)] for j in range(h)]
    
d[ch-1][cw-1] = 0
que = deque([[ch-1,cw-1]])

dx = [1,0,-1,0]
dy = [0,1,0,-1]
ddx = [1,1,-1,-1,2,2,2,2,2,1,1,0,0,-1,-1,-2,-2,-2,-2,-2]
ddy = [1,-1,1,-1,2,1,0,-1,-2,2,-2,2,-2,2,-2,2,1,0,-1,-2]
    
while que:
    y,x = que.popleft()
        
    for k in range(4):
        nx = x + dx[k]
        ny = y + dy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[y][x] != '#':
            if d[ny][nx] > d[y][x]:
                d[ny][nx] = d[y][x]
                que.append([ny,nx])
                
    for k in range(20):
        nx = x + ddx[k]
        ny = y + ddy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[y][x] != '#':
            if d[ny][nx] > d[y][x] + 1:
                d[ny][nx] = d[y][x] + 1
                que.append([ny,nx])

                
if d[dh-1][dw-1] == 10000000:
    print(-1)
else:
    print(d[dh-1][dw-1])

Fixed submission:
from collections import deque

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

c = [[] for i in range(h)]

for i in range(h):
    c[i] = input()
    
d = [[10000000 for i in range(w)] for j in range(h)]
    
d[ch-1][cw-1] = 0
que = deque([[ch-1,cw-1]])

dx = [1,0,-1,0]
dy = [0,1,0,-1]
ddx = [1,1,-1,-1,2,2,2,2,2,1,1,0,0,-1,-1,-2,-2,-2,-2,-2]
ddy = [1,-1,1,-1,2,1,0,-1,-2,2,-2,2,-2,2,-2,2,1,0,-1,-2]
    
while que:
    y,x = que.popleft()
        
    for k in range(4):
        nx = x + dx[k]
        ny = y + dy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[ny][nx] != '#':
            if d[ny][nx] > d[y][x]:
                d[ny][nx] = d[y][x]
                que.appendleft([ny,nx])
                
    for k in range(20):
        nx = x + ddx[k]
        ny = y + ddy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[ny][nx] != '#':
            if d[ny][nx] > d[y][x] + 1:
                d[ny][nx] = d[y][x] + 1
                que.append([ny,nx])

                
if d[dh-1][dw-1] == 10000000:
    print(-1)
else:
    print(d[dh-1][dw-1])

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

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

c = [[] for i in range(h)]

for i in range(h):
    c[i] = input()
d = [[10000000 for i in range(w)] for j in range(h)]
    
d[ch-1][cw-1] = 0
que = deque([[ch-1,cw-1]])

dx = [1,0,-1,0]
dy = [0,1,0,-1]
ddx = [1,1,-1,-1,2,2,2,2,2,1,1,0,0,-1,-1,-2,-2,-2,-2,-2]
ddy = [1,-1,1,-1,2,1,0,-1,-2,2,-2,2,-2,2,-2,2,1,0,-1,-2]
    
while que:
    y,x = que.popleft()
        
    for k in range(4):
        nx = x + dx[k]
        ny = y + dy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[y][x] != '#':
            if d[ny][nx] > d[y][x]:
                d[ny][nx] = d[y][x]
                que.append([ny,nx])
                
    for k in range(20):
        nx = x + ddx[k]
        ny = y + ddy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[y][x] != '#':
            if d[ny][nx] > d[y][x] + 1:
                d[ny][nx] = d[y][x] + 1
                que.append([ny,nx])

if d[dh-1][dw-1] == 10000000:
    print(-1)
else:
    print(d[dh-1][dw-1])

Fixed submission:
from collections import deque

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

c = [[] for i in range(h)]

for i in range(h):
    c[i] = input()
    
d = [[10000000 for i in range(w)] for j in range(h)]
    
d[ch-1][cw-1] = 0
que = deque([[ch-1,cw-1]])

dx = [1,0,-1,0]
dy = [0,1,0,-1]
ddx = [1,1,-1,-1,2,2,2,2,2,1,1,0,0,-1,-1,-2,-2,-2,-2,-2]
ddy = [1,-1,1,-1,2,1,0,-1,-2,2,-2,2,-2,2,-2,2,1,0,-1,-2]
    
while que:
    y,x = que.popleft()
        
    for k in range(4):
        nx = x + dx[k]
        ny = y + dy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[ny][nx] != '#':
            if d[ny][nx] > d[y][x]:
                d[ny][nx] = d[y][x]
                que.appendleft([ny,nx])
                
    for k in range(20):
        nx = x + ddx[k]
        ny = y + ddy[k]
            
        if 0<=nx and nx<w and 0<=ny and ny<h and c[ny][nx] != '#':
            if d[ny][nx] > d[y][x] + 1:
                d[ny][nx] = d[y][x] + 1
                que.append([ny,nx])

                
if d[dh-1][dw-1] == 10000000:
    print(-1)
else:
    print(d[dh-1][dw-1])