Buggy python submission (verdict: Time Limit Exceeded):
# import numpy as np
from collections import deque

H,W=map(int,input().split())
CH,CW=map(int,input().split())
DH,DW=map(int,input().split())

S=[input() for _ in range(H)]
# 後の条件分岐を簡略化するためワープしても迷路外に出ないように壁で囲む
S = ['##{}##'.format(row) for row in S]
S.insert(0, '##{}##'.format('#' * W))
S.insert(0, '##{}##'.format('#' * W))
S.append('##{}##'.format('#' * W))
S.append('##{}##'.format('#' * W))


MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W+4)] for _ in range(H+4)]
# Cost = np.full((H,W),MAX_COST)

# print(S)

ans = -1

cost0 = deque()

cost0.append((CH+1,CW+1,0))
Cost[CH+1][CW+1] = 0;

# used = set()
walk=[(1,0),(0,1),(-1,0),(0,-1)]
warp = [ (i,j) for i in range(-2,3) for j in range(-2,3) if (i, j) not in [(0, 0)] + walk ]
# print(warp)

cost1 = deque()

while cost0:
	h,w,c=cost0.popleft()
	cost1.append((h,w,c))

	for i,j in walk:
		dh = h+i
		dw = w+j
		if S[dh][dw] == '.' and c < Cost[dh][dw]:
			Cost[dh][dw] = c
			# print("updl ", i,j,dh,dw,c)
			cost0.appendleft((dh,dw,Cost[dh][dw]))

	if len(cost0) == 0:

		while cost1:
			h,w,c=cost1.popleft()
			# print(h,w,c)
			for i,j in warp:
				dh = h+i
				dw = w+j
				# print(i,j)
				if S[dh][dw] == '.' and c + 1 < Cost[dh][dw]:
					Cost[dh][dw] = c + 1
					cost0.append((dh,dw,Cost[dh][dw]))


if Cost[DH+1][DW+1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

walk=[(1,0),(0,1),(-1,0),(0,-1)]

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[DH-1][DW-1])

Buggy python submission (verdict: Time Limit Exceeded):
# import numpy as np
from collections import deque

H,W=map(int,input().split())
CH,CW=map(int,input().split())
DH,DW=map(int,input().split())

S=[input() for _ in range(H)]
# 後の条件分岐を簡略化するためワープしても迷路外に出ないように壁で囲む
S = ['##{}##'.format(row) for row in S]
S.insert(0, '##{}##'.format('#' * W))
S.insert(0, '##{}##'.format('#' * W))
S.append('##{}##'.format('#' * W))
S.append('##{}##'.format('#' * W))


MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W+4)] for _ in range(H+4)]
# Cost = np.full((H,W),MAX_COST)

# print(S)

ans = -1

cost0 = deque()

cost0.append((CH+1,CW+1,0))
Cost[CH+1][CW+1] = 0;

# used = set()
walk=[(1,0),(0,1),(-1,0),(0,-1)]
warp = [ (i,j) for i in range(-2,3) for j in range(-2,3) if (i, j) not in [(0, 0)] + walk ]
# print(warp)

cost1 = deque()

while 0 < len(cost0):
	h,w,c=cost0.popleft()
	cost1.append((h,w,c))

	for i,j in walk:
		dh = h+i
		dw = w+j
		if S[dh][dw] == '.' and c < Cost[dh][dw]:
			Cost[dh][dw] = c
			# print("updl ", i,j,dh,dw,c)
			cost0.appendleft((dh,dw,Cost[dh][dw]))

	if len(cost0) == 0:

		while 0 < len(cost1):
			h,w,c=cost1.popleft()
			# print(h,w,c)
			for i,j in warp:
				dh = h+i
				dw = w+j
				# print(i,j)
				if S[dh][dw] == '.' and c + 1 < Cost[dh][dw]:
					Cost[dh][dw] = c + 1
					cost0.append((dh,dw,Cost[dh][dw]))


if Cost[DH+1][DW+1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

walk=[(1,0),(0,1),(-1,0),(0,-1)]

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[DH-1][DW-1])

Buggy python submission (verdict: Time Limit Exceeded):
# import numpy as np
from collections import deque

H,W=map(int,input().split())
CH,CW=map(int,input().split())
DH,DW=map(int,input().split())

S=[input() for _ in range(H)]
# 後の条件分岐を簡略化するためワープしても迷路外に出ないように壁で囲む
S = ['##{}##'.format(row) for row in S]
S.insert(0, '##{}##'.format('#' * W))
S.insert(0, '##{}##'.format('#' * W))
S.append('##{}##'.format('#' * W))
S.append('##{}##'.format('#' * W))


MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W+4)] for _ in range(H+4)]
# Cost = np.full((H,W),MAX_COST)

# print(S)

ans = -1

cost0 = deque()

cost0.append((CH+1,CW+1,0))
Cost[CH+1][CW+1] = 0;

# used = set()
walk=[(1,0),(0,1),(-1,0),(0,-1)]
warp = [ (i,j) for i in range(-2,3) for j in range(-2,3) if (i, j) not in [(0, 0)] + walk ]
# print(warp)

cost1 = deque()

while 0 < len(cost0):
	h,w,c=cost0.popleft()
	cost1.append((h,w,c))

	for i,j in walk:
		dh = h+i
		dw = w+j
		if S[dh][dw] == '.' and c < Cost[dh][dw]:
			Cost[dh][dw] = c
			# print("updl ", i,j,dh,dw,c)
			cost0.append((dh,dw,Cost[dh][dw]))

	if len(cost0) == 0:

		while 0 < len(cost1):
			h,w,c=cost1.popleft()
			# print(h,w,c)
			for i,j in warp:
				dh = h+i
				dw = w+j
				# print(i,j)
				if S[dh][dw] == '.':
					if c + 1 < Cost[dh][dw]:
						Cost[dh][dw] = c + 1
						cost0.append((dh,dw,Cost[dh][dw]))


if Cost[DH+1][DW+1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

walk=[(1,0),(0,1),(-1,0),(0,-1)]

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[DH-1][DW-1])

Buggy python submission (verdict: Time Limit Exceeded):
# import numpy as np
from collections import deque

H,W=map(int,input().split())
CH,CW=map(int,input().split())
DH,DW=map(int,input().split())

S=[input() for _ in range(H)]
# 後の条件分岐を簡略化するためワープしても迷路外に出ないように壁で囲む
S = ['##{}##'.format(row) for row in S]
S.insert(0, '##{}##'.format('#' * W))
S.insert(0, '##{}##'.format('#' * W))
S.append('##{}##'.format('#' * W))
S.append('##{}##'.format('#' * W))


MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W+4)] for _ in range(H+4)]
# Cost = np.full((H,W),MAX_COST)

# print(S)

ans = -1

cost0 = deque()

cost0.append((CH+1,CW+1,0))
Cost[CH+1][CW+1] = 0;

# used = set()
walk=[(1,0),(0,1),(-1,0),(0,-1)]
warp = [ (i,j) for i in range(-2,3) for j in range(-2,3) if (i, j) not in [(0, 0)] + walk ]
# print(warp)

cost1 = deque()

while 0 < len(cost0):
	h,w,c=cost0.popleft()
	cost1.append((h,w,c))

	for i,j in walk:
		dh = h+i
		dw = w+j
		if S[dh][dw] == '.' and c < Cost[dh][dw]:
			Cost[dh][dw] = c
			# print("updl ", i,j,dh,dw,c)
			cost0.appendleft((dh,dw,Cost[dh][dw]))

	if len(cost0) == 0:

		while 0 < len(cost1):
			h,w,c=cost1.popleft()
			# print(h,w,c)
			for i,j in warp:
				dh = h+i
				dw = w+j
				# print(i,j)
				if S[dh][dw] == '.':
					if c + 1 < Cost[dh][dw]:
						Cost[dh][dw] = c + 1
						cost0.append((dh,dw,Cost[dh][dw]))


if Cost[DH+1][DW+1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

walk=[(1,0),(0,1),(-1,0),(0,-1)]

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[DH-1][DW-1])

Buggy python submission (verdict: Time Limit Exceeded):
# import numpy as np
from collections import deque

H,W=map(int,input().split())
CH,CW=map(int,input().split())
DH,DW=map(int,input().split())

S=[input() for _ in range(H)]
# 後の条件分岐を簡略化するためワープしても迷路外に出ないように壁で囲む
S = ['##{}##'.format(row) for row in S]
S.insert(0, '##{}##'.format('#' * W))
S.insert(0, '##{}##'.format('#' * W))
S.append('##{}##'.format('#' * W))
S.append('##{}##'.format('#' * W))


MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W+4)] for _ in range(H+4)]
# Cost = np.full((H,W),MAX_COST)

# print(S)

ans = -1

cost0 = deque()

cost0.append((CH+1,CW+1,0))
Cost[CH+1][CW+1] = 0;

# used = set()
walk=[(1,0),(0,1),(-1,0),(0,-1)]
warp = [ (i,j) for i in range(-2,3) for j in range(-2,3) if (i, j) not in [(0, 0)] + walk ]
# print(warp)

cost1 = deque()

while 0 < len(cost0):
	h,w,c=cost0.popleft()
	cost1.append((h,w,c))

	for i,j in walk:
		if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
			Cost[h+i][w+j] = c
			# print("updl ", i,j,h+i,w+j,c)
			cost0.appendleft((h+i,w+j,Cost[h+i][w+j]))

	if len(cost0) == 0:

		while 0 < len(cost1):
			h,w,c=cost1.popleft()
			# print(h,w,c)
			for i,j in warp:
				# print(i,j)
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						cost0.append((h+i,w+j,Cost[h+i][w+j]))


if Cost[DH+1][DW+1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

walk=[(1,0),(0,1),(-1,0),(0,-1)]

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[DH-1][DW-1])

Buggy python submission (verdict: Time Limit Exceeded):
# import numpy as np
from collections import deque

H,W=map(int,input().split())
CH,CW=map(int,input().split())
DH,DW=map(int,input().split())

S=[input() for _ in range(H)]
# 後の条件分岐を簡略化するためワープしても迷路外に出ないように壁で囲む
S = ['##{}##'.format(row) for row in S]
S.insert(0, '##{}##'.format('#' * W))
S.insert(0, '##{}##'.format('#' * W))
S.append('##{}##'.format('#' * W))
S.append('##{}##'.format('#' * W))


MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W+4)] for _ in range(H+4)]
# Cost = np.full((H,W),MAX_COST)

# print(S)

ans = -1

cost0 = deque()

cost0.append((CH+1,CW+1,0))
Cost[CH+1][CW+1] = 0;

# used = set()
walk=[(1,0),(0,1),(-1,0),(0,-1)]
warp = [ (i,j) for i in range(-2,3,1) for j in range(-2,3,1) ]
# print(warp)

cost1 = deque()

while 0 < len(cost0):
	h,w,c=cost0.popleft()
	cost1.append((h,w,c))

	for i,j in walk:
		if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
			Cost[h+i][w+j] = c
			# print("updl ", i,j,h+i,w+j,c)
			cost0.appendleft((h+i,w+j,Cost[h+i][w+j]))

	if len(cost0) == 0:

		while 0 < len(cost1):
			h,w,c=cost1.popleft()
			# print(h,w,c)
			for i,j in warp:
				# print(i,j)
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						cost0.append((h+i,w+j,Cost[h+i][w+j]))


if Cost[DH+1][DW+1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

walk=[(1,0),(0,1),(-1,0),(0,-1)]

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[DH-1][DW-1])

Buggy python submission (verdict: Time Limit Exceeded):
# import numpy as np
from collections import deque

H,W=map(int,input().split())
CH,CW=map(int,input().split())
DH,DW=map(int,input().split())

S=[input() for _ in range(H)]

MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]
# Cost = np.full((H,W),MAX_COST)

# print(S)

ans = -1

cost0 = deque()

cost0.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

# used = set()
walk=[(1,0),(0,1),(-1,0),(0,-1)]
warp = [ (i,j) for i in range(-2,3,1) for j in range(-2,3,1) ]
# print(warp)

cost1 = deque()

while 0 < len(cost0):
	h,w,c=cost0.popleft()
	cost1.append((h,w,c))

	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				cost0.appendleft((h+i,w+j,Cost[h+i][w+j]))

	if len(cost0) == 0:

		while 0 < len(cost1):
			h,w,c=cost1.popleft()
			# print(h,w,c)
			for i,j in warp:
				# print(i,j)
				if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
					if S[h+i][w+j] == '.':
						if c + 1 < Cost[h+i][w+j]:
							Cost[h+i][w+j] = c + 1
							cost0.append((h+i,w+j,Cost[h+i][w+j]))


if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

walk=[(1,0),(0,1),(-1,0),(0,-1)]

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[DH-1][DW-1])

Buggy python submission (verdict: Time Limit Exceeded):
# import numpy as np
from collections import deque

H,W=map(int,input().split())
CH,CW=map(int,input().split())
DH,DW=map(int,input().split())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]
# Cost = np.full((H,W),MAX_COST)

# print(S)

ans = -1

cost0 = deque()

cost0.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

# used = set()
walk=[(1,0),(0,1),(-1,0),(0,-1)]
warp = [ (i,j) for i in range(-2,3,1) for j in range(-2,3,1) ]
# print(warp)

cost1 = deque()

while 0 < len(cost0):
	h,w,c=cost0.popleft()
	cost1.append((h,w,c))

	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				cost0.appendleft((h+i,w+j,Cost[h+i][w+j]))

	if len(cost0) == 0:

		while 0 < len(cost1):
			h,w,c=cost1.popleft()
			# print(h,w,c)
			for i,j in warp:
				# print(i,j)
				if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
					if S[h+i][w+j] == '.':
						if c + 1 < Cost[h+i][w+j]:
							Cost[h+i][w+j] = c + 1
							cost0.append((h+i,w+j,Cost[h+i][w+j]))


if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

walk=[(1,0),(0,1),(-1,0),(0,-1)]

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[DH-1][DW-1])

Buggy python submission (verdict: Time Limit Exceeded):
# import numpy as np
from collections import deque

H,W=map(int,input().split())
CH,CW=map(int,input().split())
DH,DW=map(int,input().split())

S=[input() for _ in range(H)]
# 後の条件分岐を簡略化するためワープしても迷路外に出ないように壁で囲む
S = ['##{}##'.format(row) for row in S]
S.insert(0, '##{}##'.format('#' * W))
S.insert(0, '##{}##'.format('#' * W))
S.append('##{}##'.format('#' * W))
S.append('##{}##'.format('#' * W))

# print(S)

MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W+2)] for _ in range(H+2)]
# Cost = np.full((H,W),MAX_COST)

# print(S)

ans = -1

deq = deque()

deq.append((CH+1,CW+1,0))
Cost[CH+1][CW+1] = 0;

# used = set()
five_five = [ (i,j) for i in range(-2,3,1) for j in range(-2,3,1) ]
ffCosts = {}
for i,j in five_five:
	# print(i,j)
	if (j == 0 and (i==1 or i==-1)) or (i==0 and (j==1 or j==-1)):
		ffCosts[(i,j)] = 0
	else:
		ffCosts[(i,j)] = 1
# print(five_five)

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in five_five:
		# print(i,j)
		if S[h+i][w+j] == '.':
			cAdd = ffCosts[(i,j)]
			if c + cAdd < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c + cAdd
				if (h+i,w+j,Cost[h+i][w+j]) not in deq:
					if cAdd == 0:
						deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
					else:
						deq.append((h+i,w+j,Cost[h+i][w+j]))


# print(Cost)

if Cost[DH+1][DW+1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

walk=[(1,0),(0,1),(-1,0),(0,-1)]

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[DH-1][DW-1])

Buggy python submission (verdict: Time Limit Exceeded):
# import numpy as np
from collections import deque

H,W=map(int,input().split())
CH,CW=map(int,input().split())
DH,DW=map(int,input().split())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]
# Cost = np.full((H,W),MAX_COST)

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

# used = set()
five_five = [ (i,j) for i in range(-2,3,1) for j in range(-2,3,1) ]
ffCosts = {}
for i,j in five_five:
	# print(i,j)
	if (j == 0 and (i==1 or i==-1)) or (i==0 and (j==1 or j==-1)):
		ffCosts[(i,j)] = 0
	else:
		ffCosts[(i,j)] = 1
# print(five_five)

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in five_five:
		# print(i,j)
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.':
				cAdd = ffCosts[(i,j)]
				if c + cAdd < Cost[h+i][w+j]:
					Cost[h+i][w+j] = c + cAdd
					if (h+i,w+j,Cost[h+i][w+j]) not in deq:
						if cAdd == 0:
							deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
						else:
							deq.append((h+i,w+j,Cost[h+i][w+j]))


if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

walk=[(1,0),(0,1),(-1,0),(0,-1)]

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[DH-1][DW-1])

Buggy python submission (verdict: Time Limit Exceeded):
# import numpy as np
from collections import deque

H,W=map(int,input().split())
CH,CW=map(int,input().split())
DH,DW=map(int,input().split())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]
# Cost = np.full((H,W),MAX_COST)

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

# used = set()
five_five = [ (i,j) for i in range(-2,3,1) for j in range(-2,3,1) ]
ffCosts = {}
for i,j in five_five:
	# print(i,j)
	if (j == 0 and (i==1 or i==-1)) or (i==0 and (j==1 or j==-1)):
		ffCosts[(i,j)] = 0
	else:
		ffCosts[(i,j)] = 1
# print(five_five)

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in five_five:
		# print(i,j)
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.':
				cAdd = ffCosts[(i,j)]
				if c + cAdd < Cost[h+i][w+j]:
					Cost[h+i][w+j] = c + cAdd
					if cAdd == 0:
						deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
					else:
						deq.append((h+i,w+j,Cost[h+i][w+j]))

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

walk=[(1,0),(0,1),(-1,0),(0,-1)]

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[DH-1][DW-1])

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

H,W=map(int,input().split())
CH,CW=map(int,input().split())
DH,DW=map(int,input().split())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
# Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]
Cost = np.full((H,W),MAX_COST)

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

# used = set()
five_five = [ (i,j) for i in range(-2,3,1) for j in range(-2,3,1) ]
# print(five_five)

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in five_five:
		# print(i,j)
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.':
				if (j == 0 and (i==1 or i==-1)) or (i==0 and (j==1 or j==-1)):
					if c < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c
						deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
				elif c + 1 < Cost[h+i][w+j]:
					Cost[h+i][w+j] = c + 1
					deq.append((h+i,w+j,Cost[h+i][w+j]))
					# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

walk=[(1,0),(0,1),(-1,0),(0,-1)]

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

# used = set()
five_five = [ (i,j) for i in range(-2,3,1) for j in range(-2,3,1) ]
# print(five_five)

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in five_five:
		# print(i,j)
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.':
				if (j == 0 and (i==1 or i==-1)) or (i==0 and (j==1 or j==-1)):
					if c < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c
						deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
				elif c + 1 < Cost[h+i][w+j]:
					Cost[h+i][w+j] = c + 1
					deq.append((h+i,w+j,Cost[h+i][w+j]))
					# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

walk=[(1,0),(0,1),(-1,0),(0,-1)]

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

# used = set()
five_five = [ (i,j) for i in range(-2,3,1) for j in range(-2,3,1) ]
# print(five_five)

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in five_five:
		# print(i,j)
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.':
				if (j == 0 and abs(i)==1) or (i==0 and abs(j)==1):
					if c < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c
						deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
				elif c + 1 < Cost[h+i][w+j]:
					Cost[h+i][w+j] = c + 1
					deq.append((h+i,w+j,Cost[h+i][w+j]))
					# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

walk=[(1,0),(0,1),(-1,0),(0,-1)]

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if (j == 0 and abs(i)==1) or (i==0 and abs(j)==1):
						if c < Cost[h+i][w+j]:
							Cost[h+i][w+j] = c
							deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
					elif c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[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())

S=[list(input()) for _ in range(H)]
MAX_COST = 10 ** 9
Cost=[ [ MAX_COST for _ in range(W)] for _ in range(H)]

# print(S)

ans = -1

deq = deque()

deq.append((CH-1,CW-1,0))
Cost[CH-1][CW-1] = 0;

walk=[(1,0),(0,1),(-1,0),(0,-1)]

# used = set()

while 0 < len(deq):
	h,w,c=deq.popleft()
	# print(h,w,c)
	for i,j in walk:
		if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
			if S[h+i][w+j] == '.' and c < Cost[h+i][w+j]:
				Cost[h+i][w+j] = c
				# print("updl ", i,j,h+i,w+j,c)
				deq.appendleft((h+i,w+j,Cost[h+i][w+j]))
	for i in range(-2,3,1):
		for j in range(-2,3,1):
			# print(i,j)
			if 0 <= h+i and h+i < H and 0 <= w+j and w+j < W:
				if S[h+i][w+j] == '.':
					if c + 1 < Cost[h+i][w+j]:
						Cost[h+i][w+j] = c + 1
						deq.append((h+i,w+j,Cost[h+i][w+j]))
						# print("updr ", h+i,w+j,Cost[h+i][w+j])

if Cost[DH-1][DW-1] == MAX_COST:
	print(-1)
else:
	print(Cost[DH-1][DW-1])