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

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[i for i in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for i in temp:
            nexty=y+i
            if 0<=nexty<h:
                s2=s[nexty]
                for j in temp:
                    nextx=x+j
                    if 0<=nextx<w and s[nexty][nextx]>=0:
                        dist=s2[nextx]
                        if i*i+j*j<=1 and dist>s1:
                            s[nexty][nextx]=s1
                            que.append([nexty,nextx])
                        elif dist>s1+1:
                            s[nexty][nextx]=s1+1
                            que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()


Fixed submission:
from collections import deque
from sys import stdin

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[i for i in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for i in temp:
            nexty=y+i
            if 0<=nexty<h:
                s2=s[nexty]
                for j in temp:
                    nextx=x+j
                    if 0<=nextx<w and s2[nextx]>=0:
                        dist=s2[nextx]
                        if i*i+j*j<=1 and dist>s1:
                            s[nexty][nextx]=s1
                            que.appendleft([nexty,nextx])
                        elif dist>s1+1:
                            s[nexty][nextx]=s1+1
                            que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()

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

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[(i,j) for i in range(-2,3) for j in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for (i,j) in temp:
            nexty,nextx=y+i,x+j
            if 0<=nexty<h and 0<=nextx<w and s[nexty][nextx]>=0:
                dist=s[nexty][nextx]
                if i*i+j*j<=1 and dist>s1:
                    s[nexty][nextx]=s1
                    que.append([nexty,nextx])
                elif dist>s1+1:
                    s[nexty][nextx]=s1+1
                    que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()


Fixed submission:
from collections import deque
from sys import stdin

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[i for i in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for i in temp:
            nexty=y+i
            if 0<=nexty<h:
                s2=s[nexty]
                for j in temp:
                    nextx=x+j
                    if 0<=nextx<w and s2[nextx]>=0:
                        dist=s2[nextx]
                        if i*i+j*j<=1 and dist>s1:
                            s[nexty][nextx]=s1
                            que.appendleft([nexty,nextx])
                        elif dist>s1+1:
                            s[nexty][nextx]=s1+1
                            que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()

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

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[(i,j) for i in range(-2,3) for j in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        nexty,nextx=y+i,x+j
        for (i,j) in temp:
            if 0<=nexty<h and 0<=nextx<w and s[nexty][nextx]>=0:
                dist=s[nexty][nextx]
                if i*i+j*j<=1 and dist>s1:
                    s[nexty][nextx]=s1
                    que.append([nexty,nextx])
                elif dist>s1+1:
                    s[nexty][nextx]=s1+1
                    que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()


Fixed submission:
from collections import deque
from sys import stdin

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[i for i in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for i in temp:
            nexty=y+i
            if 0<=nexty<h:
                s2=s[nexty]
                for j in temp:
                    nextx=x+j
                    if 0<=nextx<w and s2[nextx]>=0:
                        dist=s2[nextx]
                        if i*i+j*j<=1 and dist>s1:
                            s[nexty][nextx]=s1
                            que.appendleft([nexty,nextx])
                        elif dist>s1+1:
                            s[nexty][nextx]=s1+1
                            que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()

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

def bfs():
    h,w=map(int,input().split())
    sy,sx=map(int,input().split())
    gy,gx=map(int,input().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(input()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[(1,0),(0,1),(-1,0),(0,-1),(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)]
    while que:
        y,x=que.popleft()
        for i,j in temp:
            if 0<=y+i<h and 0<=x+j<w and s[y+i][x+j]>=0:
                nexty,nextx=y+i,x+j
                dist=s[nexty][nextx]
                if abs(i)+abs(j)<=1 and dist>s[y][x]:
                    s[nexty][nextx]=s[y][x]
                    que.append([nexty,nextx])
                elif dist>s[y][x]+1:
                    s[nexty][nextx]=s[y][x]+1
                    que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])

bfs()


Fixed submission:
from collections import deque
from sys import stdin

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[i for i in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for i in temp:
            nexty=y+i
            if 0<=nexty<h:
                s2=s[nexty]
                for j in temp:
                    nextx=x+j
                    if 0<=nextx<w and s2[nextx]>=0:
                        dist=s2[nextx]
                        if i*i+j*j<=1 and dist>s1:
                            s[nexty][nextx]=s1
                            que.appendleft([nexty,nextx])
                        elif dist>s1+1:
                            s[nexty][nextx]=s1+1
                            que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()

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


h,w=map(int,input().split())
c=list(map(int,input().split()))
d=list(map(int,input().split()))
s=[list(input()) for _ in range(h)]
dict={".":10000000,"#":-1}
sy,sx,gy,gx=c[0]-1,c[1]-1,d[0]-1,d[1]-1
s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
s[sy][sx]=0
que=deque([[sy,sx]])
temp=[(1,0),(0,1),(-1,0),(0,-1),(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)]
while que:
    y,x=que.popleft()
    for i,j in temp:
        if 0<=y+i<h and 0<=x+j<w and s[y+i][x+j]>=0:
            nexty,nextx=y+i,x+j
            dist=s[nexty][nextx]
            if i*i+j*j==1 and dist>s[y][x]:
                s[nexty][nextx]=s[y][x]
                que.append([nexty,nextx])
            elif dist>s[y][x]+1:
                s[nexty][nextx]=s[y][x]+1
                que.append([nexty,nextx])

if s[gy][gx]==10000000:
    print(-1)
else:
    print(s[gy][gx])


Fixed submission:
from collections import deque
from sys import stdin

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[i for i in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for i in temp:
            nexty=y+i
            if 0<=nexty<h:
                s2=s[nexty]
                for j in temp:
                    nextx=x+j
                    if 0<=nextx<w and s2[nextx]>=0:
                        dist=s2[nextx]
                        if i*i+j*j<=1 and dist>s1:
                            s[nexty][nextx]=s1
                            que.appendleft([nexty,nextx])
                        elif dist>s1+1:
                            s[nexty][nextx]=s1+1
                            que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()

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


h,w=map(int,input().split())
c=list(map(int,input().split()))
d=list(map(int,input().split()))
s=[list(input()) for _ in range(h)]
dict={".":1000000,"#":-1}
s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]

s[c[0]-1][c[1]-1]=0
que=deque([[c[0]-1,c[1]-1]])
temp=[(1,0),(0,1),(-1,0),(0,-1),(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)]
while que:
    y,x=que.popleft()
    for i,j in temp:
        if 0<=y+i<h and 0<=x+j<w and s[y+i][x+j]>=0:
            nexty,nextx=y+i,x+j
            dist=s[nexty][nextx]
            if i*i+j*j==1 and dist>s[y][x]:
                s[nexty][nextx]=s[y][x]
                que.append([nexty,nextx])
            elif dist>s[y][x]+1:
                s[nexty][nextx]=s[y][x]+1
                que.append([nexty,nextx])

if s[d[0]-1][d[1]-1]==1000000:
    print(-1)
else:
    print(s[d[0]-1][d[1]-1])


Fixed submission:
from collections import deque
from sys import stdin

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[i for i in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for i in temp:
            nexty=y+i
            if 0<=nexty<h:
                s2=s[nexty]
                for j in temp:
                    nextx=x+j
                    if 0<=nextx<w and s2[nextx]>=0:
                        dist=s2[nextx]
                        if i*i+j*j<=1 and dist>s1:
                            s[nexty][nextx]=s1
                            que.appendleft([nexty,nextx])
                        elif dist>s1+1:
                            s[nexty][nextx]=s1+1
                            que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()

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


h,w=map(int,input().split())
c=list(map(int,input().split()))
d=list(map(int,input().split()))
s=[list(input()) for _ in range(h)]
dict={".":10000000,"#":-1}
s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]

s[c[0]-1][c[1]-1]=0
que=deque([[c[0]-1,c[1]-1]])
temp=[(1,0),(0,1),(-1,0),(0,-1),(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)]
while que:
    y,x=que.popleft()
    for i,j in temp:
        if 0<=y+i<h and 0<=x+j<w and s[y+i][x+j]>=0:
            nexty,nextx=y+i,x+j
            dist=s[nexty][nextx]
            if i*i+j*j==1 and dist>s[y][x]:
                s[nexty][nextx]=s[y][x]
                que.append([nexty,nextx])
            elif dist>s[y][x]+1:
                s[nexty][nextx]=s[y][x]+1
                que.append([nexty,nextx])

if s[d[0]-1][d[1]-1]==10000000:
    print(-1)
else:
    print(s[d[0]-1][d[1]-1])


Fixed submission:
from collections import deque
from sys import stdin

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[i for i in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for i in temp:
            nexty=y+i
            if 0<=nexty<h:
                s2=s[nexty]
                for j in temp:
                    nextx=x+j
                    if 0<=nextx<w and s2[nextx]>=0:
                        dist=s2[nextx]
                        if i*i+j*j<=1 and dist>s1:
                            s[nexty][nextx]=s1
                            que.appendleft([nexty,nextx])
                        elif dist>s1+1:
                            s[nexty][nextx]=s1+1
                            que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()

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


h,w=map(int,input().split())
c=list(map(int,input().split()))
d=list(map(int,input().split()))
s=[list(input()) for _ in range(h)]


for y in range(h):
    for x in range(w):
        if s[y][x]=='.':
            s[y][x]=10000000


s[c[0]-1][c[1]-1]=0
que=deque([[c[0]-1,c[1]-1]])
temp=[(1,0),(0,1),(-1,0),(0,-1),(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)]
while que:
    y,x=que.popleft()
    for i,j in temp:
        if 0<=y+i<h and 0<=x+j<w and s[y+i][x+j]!="#":
            nexty,nextx=y+i,x+j
            dist=s[nexty][nextx]
            if i*i+j*j==1 and dist>s[y][x]:
                s[nexty][nextx]=s[y][x]
                que.append([nexty,nextx])
            elif dist>s[y][x]+1:
                s[nexty][nextx]=s[y][x]+1
                que.append([nexty,nextx])

if s[d[0]-1][d[1]-1]==10000000:
    print(-1)
else:
    print(s[d[0]-1][d[1]-1])


Fixed submission:
from collections import deque
from sys import stdin

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[i for i in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for i in temp:
            nexty=y+i
            if 0<=nexty<h:
                s2=s[nexty]
                for j in temp:
                    nextx=x+j
                    if 0<=nextx<w and s2[nextx]>=0:
                        dist=s2[nextx]
                        if i*i+j*j<=1 and dist>s1:
                            s[nexty][nextx]=s1
                            que.appendleft([nexty,nextx])
                        elif dist>s1+1:
                            s[nexty][nextx]=s1+1
                            que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()

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


h,w=map(int,input().split())
c=list(map(int,input().split()))
d=list(map(int,input().split()))
s=[list(input()) for _ in range(h)]


for y in range(h):
    for x in range(w):
        if s[y][x]=='.':
            s[y][x]=10000000


s[c[0]-1][c[1]-1]=0
que=deque([[c[0]-1,c[1]-1]])
temp=[(1,0),(0,1),(-1,0),(0,-1),(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)]
while que:
    y,x=que.popleft()
    for i,j in temp:
        if 0<=y+i<h and 0<=x+j<w and s[y+i][x+j]!="#":
            nexty,nextx=y+i,x+j
            dist=s[nexty][nextx]
            if i*i+j*j==1 and dist>s[y][x:
                s[nexty][nextx]=s[y][x]
                que.append([nexty,nextx])
            elif dist>s[y][x]+1:
                s[nexty][nextx]=s[y][x]+1
                que.append([nexty,nextx])

if s[d[0]-1][d[1]-1]==10000000:
    print(-1)
else:
    print(s[d[0]-1][d[1]-1])


Fixed submission:
from collections import deque
from sys import stdin

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[i for i in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for i in temp:
            nexty=y+i
            if 0<=nexty<h:
                s2=s[nexty]
                for j in temp:
                    nextx=x+j
                    if 0<=nextx<w and s2[nextx]>=0:
                        dist=s2[nextx]
                        if i*i+j*j<=1 and dist>s1:
                            s[nexty][nextx]=s1
                            que.appendleft([nexty,nextx])
                        elif dist>s1+1:
                            s[nexty][nextx]=s1+1
                            que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()

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


h,w=map(int,input().split())
c=list(map(int,input().split()))
d=list(map(int,input().split()))
s=[list(input()) for _ in range(h)]


for y in range(h):
    s[y]=[10000000 if s[y][x]=="." else s[y][x] for x in range(w)]


s[c[0]-1][c[1]-1]=0
que=deque([[c[0]-1,c[1]-1]])
while que:
    y,x=que.popleft()
    for i,j in [(1,0),(0,1),(-1,0),(0,-1),(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)]:
        if 0<=y+i<h and 0<=x+j<w:
            nexty,nextx=y+i,x+j
            dist=s[nexty][nextx]
            if dist!='#':
                if i*i+j*j==1:
                    if dist>s[y][x]:
                        s[nexty][nextx]=s[y][x]
                        que.append([nexty,nextx])
                elif dist>s[y][x]+1:
                    s[nexty][nextx]=s[y][x]+1
                    que.append([nexty,nextx])

if s[d[0]-1][d[1]-1]==10000000:
    print(-1)
else:
    print(s[d[0]-1][d[1]-1])


Fixed submission:
from collections import deque
from sys import stdin

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[i for i in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for i in temp:
            nexty=y+i
            if 0<=nexty<h:
                s2=s[nexty]
                for j in temp:
                    nextx=x+j
                    if 0<=nextx<w and s2[nextx]>=0:
                        dist=s2[nextx]
                        if i*i+j*j<=1 and dist>s1:
                            s[nexty][nextx]=s1
                            que.appendleft([nexty,nextx])
                        elif dist>s1+1:
                            s[nexty][nextx]=s1+1
                            que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()

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


h,w=map(int,input().split())
c=list(map(int,input().split()))
d=list(map(int,input().split()))
s=[list(input()) for _ in range(h)]


for y in range(h):
    for x in range(w):
        if s[y][x]=='.':
            s[y][x]=10000000


s[c[0]-1][c[1]-1]=0
que=deque([[c[0]-1,c[1]-1]])
while que:
    y,x=que.popleft()
    for i,j in [(1,0),(0,1),(-1,0),(0,-1),(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)]:
        if 0<=y+i<h and 0<=x+j<w:
            nexty,nextx=y+i,x+j
            dist=s[nexty][nextx]
            if dist!='#':
                if i*i+j*j==1:
                    if dist>s[y][x]:
                        s[nexty][nextx]=s[y][x]
                        que.append([nexty,nextx])
                elif dist>s[y][x]+1:
                    s[nexty][nextx]=s[y][x]+1
                    que.append([nexty,nextx])

if s[d[0]-1][d[1]-1]==10000000:
    print(-1)
else:
    print(s[d[0]-1][d[1]-1])


Fixed submission:
from collections import deque
from sys import stdin

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[i for i in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for i in temp:
            nexty=y+i
            if 0<=nexty<h:
                s2=s[nexty]
                for j in temp:
                    nextx=x+j
                    if 0<=nextx<w and s2[nextx]>=0:
                        dist=s2[nextx]
                        if i*i+j*j<=1 and dist>s1:
                            s[nexty][nextx]=s1
                            que.appendleft([nexty,nextx])
                        elif dist>s1+1:
                            s[nexty][nextx]=s1+1
                            que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()

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


h,w=map(int,input().split())
c=list(map(int,input().split()))
d=list(map(int,input().split()))
s=[list(input()) for _ in range(h)]


def bfs():
    for y in range(h):
        for x in range(w):
            if s[y][x]=='.':
                s[y][x]=math.inf


    s[c[0]-1][c[1]-1]=0
    que=deque([[c[0]-1,c[1]-1]])
    while que:
        y,x=que.popleft()
        for i,j in [(1,0),(0,1),(-1,0),(0,-1),(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)]:
            if 0<=y+i<h and 0<=x+j<w:
                nexty,nextx=y+i,x+j
                dist=s[nexty][nextx]
                if dist!='#':
                    if i*i+j*j==1:
                        if dist>s[y][x]:
                            s[nexty][nextx]=s[y][x]
                            que.append([nexty,nextx])
                    elif dist>s[y][x]+1:
                        s[nexty][nextx]=s[y][x]+1
                        que.append([nexty,nextx])

    if s[d[0]-1][d[1]-1]==math.inf:
        print(-1)
    else:
        print(s[d[0]-1][d[1]-1])

bfs()


Fixed submission:
from collections import deque
from sys import stdin

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[i for i in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for i in temp:
            nexty=y+i
            if 0<=nexty<h:
                s2=s[nexty]
                for j in temp:
                    nextx=x+j
                    if 0<=nextx<w and s2[nextx]>=0:
                        dist=s2[nextx]
                        if i*i+j*j<=1 and dist>s1:
                            s[nexty][nextx]=s1
                            que.appendleft([nexty,nextx])
                        elif dist>s1+1:
                            s[nexty][nextx]=s1+1
                            que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()

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


h,w=map(int,input().split())
c=list(map(int,input().split()))
d=list(map(int,input().split()))
s=[list(input()) for _ in range(h)]


def bfs():
    for y in range(h):
        for x in range(w):
            if s[y][x]=='.':
                s[y][x]=math.inf


    s[c[0]-1][c[1]-1]=0
    que=deque([[c[0]-1,c[1]-1]])
    while que:
        y,x=que.popleft()
        for i,j in [(1,0),(0,1),(-1,0),(0,-1)]:
            if 0<=y+i<h and 0<=x+j<w:
                nexty,nextx=y+i,x+j
                dist=s[nexty][nextx]
                if dist!='#':
                    if dist>s[y][x]:
                        s[nexty][nextx]=s[y][x]
                        que.append([nexty,nextx])

        for k,l in [(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)]:
            if 0<=y+k<h and 0<=x+l<w:
                warpy,warpx=y+k,x+l
                dist=s[warpy][warpx]
                if dist!='#':
                    if dist>s[y][x]+1:
                        s[warpy][warpx]=s[y][x]+1
                        que.append([warpy,warpx])
    if s[d[0]-1][d[1]-1]==math.inf:
        print(-1)
    else:
        print(s[d[0]-1][d[1]-1])

bfs()


Fixed submission:
from collections import deque
from sys import stdin

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[i for i in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for i in temp:
            nexty=y+i
            if 0<=nexty<h:
                s2=s[nexty]
                for j in temp:
                    nextx=x+j
                    if 0<=nextx<w and s2[nextx]>=0:
                        dist=s2[nextx]
                        if i*i+j*j<=1 and dist>s1:
                            s[nexty][nextx]=s1
                            que.appendleft([nexty,nextx])
                        elif dist>s1+1:
                            s[nexty][nextx]=s1+1
                            que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()

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


h,w=map(int,input().split())
c=list(map(int,input().split()))
d=list(map(int,input().split()))
s=[list(input()) for _ in range(h)]


def bfs():
    for y in range(h):
        for x in range(w):
            if s[y][x]=='.':
                s[y][x]=math.inf


    s[c[0]-1][c[1]-1]=0
    que=deque([[c[0]-1,c[1]-1]])
    while que:
        y,x=que.popleft()
        for i,j in [(1,0),(0,1),(-1,0),(0,-1)]:
            if 0<=y+i<h and 0<=x+j<w:
                nexty,nextx=y+i,x+j
                dist=s[nexty][nextx]
                if dist!='#':
                    if dist>s[y][x]:
                        s[nexty][nextx]=s[y][x]
                        que.append([nexty,nextx])

        for k,l in [(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)]:
            if 0<=y+k<h and 0<=x+l<w:
                warpy,warpx=y+k,x+l
                dist=s[warpy][warpx]
                if dist!='#':
                    if dist>s[y][x]+1:
                        s[warpy][warpx]=s[y][x]+1
                        que.append([warpy,warpx])
    if s[d[0]-1][d[1]-1]==math.inf:
        print(-1)
    else:
        print(s[d[0]-1][d[1]-1])

bfs()


Fixed submission:
from collections import deque
from sys import stdin

def bfs():
    readline=stdin.readline
    h,w=map(int,readline().split())
    sy,sx=map(int,readline().split())
    gy,gx=map(int,readline().split())
    sy-=1;sx-=1;gy-=1;gx-=1
    s=[list(readline()) for _ in range(h)]
    dict={".":10000000,"#":-1}
    s=[[dict[s[y][x]] for x in range(w)]for y in range(h)]
    s[sy][sx]=0
    que=deque([[sy,sx]])
    temp=[i for i in range(-2,3)]
    while que:
        y,x=que.popleft()
        s1=s[y][x]
        for i in temp:
            nexty=y+i
            if 0<=nexty<h:
                s2=s[nexty]
                for j in temp:
                    nextx=x+j
                    if 0<=nextx<w and s2[nextx]>=0:
                        dist=s2[nextx]
                        if i*i+j*j<=1 and dist>s1:
                            s[nexty][nextx]=s1
                            que.appendleft([nexty,nextx])
                        elif dist>s1+1:
                            s[nexty][nextx]=s1+1
                            que.append([nexty,nextx])

    if s[gy][gx]==10000000:
        print(-1)
    else:
        print(s[gy][gx])
bfs()