Buggy python submission (verdict: Time Limit Exceeded):
H, W = map(int,input().split())
ch, cw = map(int, input().split())
dh, dw = map(int, input().split())
c = [["#"]*(W+4) for _ in range(H+4)]
for y in range(H):
    c[y+2] = *list("##"+input()+"##"), 
inf = H*W
m = [[inf]*W for _ in range(H)]
m[ch-1][cw-1] = 0
drs = [[-1,0],[1,0],[0,0],[0,-1],[0,1]]
warps = [[-2,-2],[-2,-1],[-2,0],[-2,1],[-2,2],
        [2,-2],[2,-1],[2,0],[2,1],[2,2],
        [-1,-2],[0,-2],[1,-2],
        [-1,2],[0,2],[1,2],
        [-1,-1],[-1,1],[1,-1],[1,1]
       ]

s = 0
yx = [[ch+1, cw+1]]
notgoal = True
yxwarp = True
while notgoal and yxwarp:
    yxwarp = []
    while yx:
        yx2 = []
        for y,x in yx:
            for dy, dx in drs:
                x2 = x+dx
                y2 = y+dy
                if c[y2][x2] == "." and m[y2-2][x2-2] == inf:
                    m[y2-2][x2-2] = s
                    if (y2,x2) == (dh+1,dw+1):
                        notgoal = False
                        break
                    else:
                        yx2.append([y2, x2])
                        continue
                    break
            for dy, dx in warps:
                x2 = x+dx
                y2 = y+dy
                if c[y2][x2] == "." and m[y2-2][x2-2] == inf:
                    yxwarp.append([y2, x2])
        yx = yx2
    s += 1
    yx = yxwarp
    
if notgoal:
    print("-1")
else:
    print(s-1)

Fixed submission:
from collections import deque

Y, X = map(int,input().split())
sy, sx = map(int, input().split())
gy, gx = map(int, input().split())
s = [["#"]*(X+4) for _ in range(Y+4)]
for y in range(Y):
    s[y+2] = *list("##"+input()+"##"), 
inf = Y*X
c = [[inf]*X for _ in range(Y)]
c[sy-1][sx-1] = 0
drs = [[-1,0],[1,0],[0,0],[0,-1],[0,1]]
dr2s = [[-2,-2],[-2,-1],[-2,0],[-2,1],[-2,2],
        [2,-2],[2,-1],[2,0],[2,1],[2,2],
        [-1,-2],[0,-2],[1,-2],
        [-1,2],[0,2],[1,2],
        [-1,-1],[-1,1],[1,-1],[1,1]
       ]

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

while q:
    y,x = q.popleft()
    cost = c[y][x]
    for dx,dy in drs:
        x2 = x+dx
        y2 = y+dy
        if s[y2+2][x2+2] == "." and c[y2][x2] > cost:
            c[y2][x2] = cost
            q.appendleft((y2,x2))
    for dy, dx in dr2s:
        x2 = x+dx
        y2 = y+dy
        if s[y2+2][x2+2] == "." and c[y2][x2] > cost+1:
            c[y2][x2] = cost+1
            q.append((y2,x2))
    
if c[gy-1][gx-1] == inf:
    print("-1")
else:
    print(c[gy-1][gx-1])

Buggy python submission (verdict: Time Limit Exceeded):
H, W = map(int,input().split())
ch, cw = map(int, input().split())
dh, dw = map(int, input().split())
c = [["#"]*(W+4) for _ in range(H+4)]
for y in range(H):
    c[y+2] = *list("##"+input()+"##"), 
inf = H*W
m = [[inf]*W for _ in range(H)]
m[ch-1][cw-1] = 0
drs = [[-1,0],[1,0],[0,0],[0,-1],[0,1]]
warps = [[-2,-2],[-2,-1],[-2,0],[-2,1],[-2,2],
        [2,-2],[2,-1],[2,0],[2,1],[2,2],
        [-1,-2],[0,-2],[1,-2],
        [-1,2],[0,2],[1,2],
        [-1,-1],[-1,1],[1,-1],[1,1]
       ]

s = 0
yx = [[ch+1, cw+1]]
notgoal = True
yxwarp = True
while notgoal and yxwarp:
    yxwarp = []
    while yx:
        yx2 = []
        for y,x in yx:
            for dy, dx in drs:
                x2 = x+dx
                y2 = y+dy
                if c[y2][x2] == "." and m[y2-2][x2-2] == inf:
                    m[y2-2][x2-2] = s
                    if (y2,x2) == (dh+1,dw+1):
                        notgoal = False
                        break
                    else:
                        yx2.append([y2, x2])
                        continue
                    break
            for dy, dx in warps:
                x2 = x+dx
                y2 = y+dy
                if c[y2][x2] == "." and m[y2-2][x2-2] == inf:
                    yxwarp.append([y2, x2])
        yx = yx2
    s += 1
    yx = yxwarp
    
if notgoal:
    print("-1")
else:
    print(s-1)

Fixed submission:
from collections import deque

Y, X = map(int,input().split())
sy, sx = map(int, input().split())
gy, gx = map(int, input().split())
s = [["#"]*(X+4) for _ in range(Y+4)]
for y in range(Y):
    s[y+2] = *list("##"+input()+"##"), 
inf = Y*X
c = [[inf]*X for _ in range(Y)]
c[sy-1][sx-1] = 0
drs = [[-1,0],[1,0],[0,0],[0,-1],[0,1]]
dr2s = [[-2,-2],[-2,-1],[-2,0],[-2,1],[-2,2],
        [2,-2],[2,-1],[2,0],[2,1],[2,2],
        [-1,-2],[0,-2],[1,-2],
        [-1,2],[0,2],[1,2],
        [-1,-1],[-1,1],[1,-1],[1,1]
       ]

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

while q:
    y,x = q.popleft()
    cost = c[y][x]
    for dx,dy in drs:
        x2 = x+dx
        y2 = y+dy
        if s[y2+2][x2+2] == "." and c[y2][x2] > cost:
            c[y2][x2] = cost
            q.appendleft((y2,x2))
    for dy, dx in dr2s:
        x2 = x+dx
        y2 = y+dy
        if s[y2+2][x2+2] == "." and c[y2][x2] > cost+1:
            c[y2][x2] = cost+1
            q.append((y2,x2))
    
if c[gy-1][gx-1] == inf:
    print("-1")
else:
    print(c[gy-1][gx-1])