Buggy python submission (verdict: Time Limit Exceeded):
import sys
def input():
	return sys.stdin.readline()[:-1]
from collections import deque
H, W, K = map(int, input().split())
sh, sw, gh, gw = map(int, input().split())
c = "@" * (W+2)
for _ in range(H):
	c += "@" + input() + "@"
c += "@" * (W+2)
#c = ["@" * (W+2)] + ["@" + input() + "@" for _ in range(H)] + ["@" * (W+2)]
INF = 10**6+5
dist = [INF for _ in range((W+2) * (H+2))]
dist[sh*(W+2)+sw] = 0
q = deque()
q.append(sh*(W+2)+sw)
DI = [1, 0, -1, 0]
DJ = [0, 1, 0, -1]
while q:
	l = q.popleft()
	i, j = l//(W+2), l%(W+2)
	for di, dj in zip(DI, DJ):
		for k in range(1, K+1):
			ii, jj = i+di*k, j+dj*k
			if c[ii*(W+2)+jj] == "." and dist[ii*(W+2)+jj] > dist[i*(W+2)+j]:
				dist[ii*(W+2)+jj] = dist[i*(W+2)+j] + 1
				if ii == gh and jj == gw:
					print(dist[ii*(W+2)+jj])
					sys.exit()
				q.append(ii*(W+2) + jj)
			else:
				break
print(-1)

Fixed submission:
import sys
def input():
	return sys.stdin.readline()[:-1]
from collections import deque
H, W, K = map(int, input().split())
sh, sw, gh, gw = map(int, input().split())
c = ["@" * (W+2)] + ["@" + input() + "@" for _ in range(H)] + ["@" * (W+2)]
INF = 10**6+5
dist = [[INF for _ in range(W+2)] for _ in range(H+2)]
dist[sh][sw] = 0
q = deque()
q.append(sh*(W+2)+sw)
DI = [1, 0, -1, 0]
DJ = [0, 1, 0, -1]
while q:
	l = q.popleft()
	i, j = l//(W+2), l%(W+2)
	for di, dj in zip(DI, DJ):
		for k in range(1, K+1):
			ii, jj = i+di*k, j+dj*k
			if c[ii][jj] == "@":
				break
			if dist[ii][jj] <= dist[i][j]:
				break
			if dist[ii][jj] > dist[i][j] + 1:
				dist[ii][jj] = dist[i][j] + 1
				if ii == gh and jj == gw:
					print(dist[ii][jj])
					sys.exit()
				q.append(ii*(W+2) + jj)
print(-1)

Buggy python submission (verdict: Time Limit Exceeded):
import sys
def input():
	return sys.stdin.readline()[:-1]
from collections import deque
H, W, K = map(int, input().split())
sh, sw, gh, gw = map(int, input().split())
c = ["@" * (W+2)] + ["@" + input() + "@" for _ in range(H)] + ["@" * (W+2)]
INF = 10**6+5
dist = [INF for _ in range((W+2) * (H+2))]
dist[sh*(W+2)+sw] = 0
q = deque()
q.append(sh*(W+2)+sw)
DI = [1, 0, -1, 0]
DJ = [0, 1, 0, -1]
while q:
	l = q.popleft()
	i, j = l//(W+2), l%(W+2)
	for di, dj in zip(DI, DJ):
		for k in range(1, K+1):
			ii, jj = i+di*k, j+dj*k
			if c[ii][jj] == "." and dist[ii*(W+2)+jj] > dist[i*(W+2)+j]:
				dist[ii*(W+2)+jj] = dist[i*(W+2)+j] + 1
				if ii == gh and jj == gw:
					print(dist[ii*(W+2)+jj])
					sys.exit()
				q.append(ii*(W+2) + jj)
			else:
				break
print(-1)

Fixed submission:
import sys
def input():
	return sys.stdin.readline()[:-1]
from collections import deque
H, W, K = map(int, input().split())
sh, sw, gh, gw = map(int, input().split())
c = ["@" * (W+2)] + ["@" + input() + "@" for _ in range(H)] + ["@" * (W+2)]
INF = 10**6+5
dist = [[INF for _ in range(W+2)] for _ in range(H+2)]
dist[sh][sw] = 0
q = deque()
q.append(sh*(W+2)+sw)
DI = [1, 0, -1, 0]
DJ = [0, 1, 0, -1]
while q:
	l = q.popleft()
	i, j = l//(W+2), l%(W+2)
	for di, dj in zip(DI, DJ):
		for k in range(1, K+1):
			ii, jj = i+di*k, j+dj*k
			if c[ii][jj] == "@":
				break
			if dist[ii][jj] <= dist[i][j]:
				break
			if dist[ii][jj] > dist[i][j] + 1:
				dist[ii][jj] = dist[i][j] + 1
				if ii == gh and jj == gw:
					print(dist[ii][jj])
					sys.exit()
				q.append(ii*(W+2) + jj)
print(-1)

Buggy python submission (verdict: Time Limit Exceeded):
import sys
def input():
	return sys.stdin.readline()[:-1]
from collections import deque
H, W, K = map(int, input().split())
sh, sw, gh, gw = map(int, input().split())
c = ["@" * (W+2)] + ["@" + input() + "@" for _ in range(H)] + ["@" * (W+2)]
INF = 10**7
dist = [[INF for _ in range(W+2)] for _ in range(H+2)]
dist[sh][sw] = 0
q = deque()
q.append(sh*(W+2)+sw)
DI = [1, 0, -1, 0]
DJ = [0, 1, 0, -1]
while q:
	l = q.popleft()
	i, j = l//(W+2), l%(W+2)
	for di, dj in zip(DI, DJ):
		for k in range(1, K+1):
			ii, jj = i+di*k, j+dj*k
			if c[ii][jj] == "." and dist[ii][jj] > dist[i][j]:
				dist[ii][jj] = dist[i][j] + 1
				if ii == gh and jj == gw:
					print(dist[ii][jj])
					sys.exit()
				q.append(ii*(W+2) + jj)
			else:
				break
print(-1)

Fixed submission:
import sys
def input():
	return sys.stdin.readline()[:-1]
from collections import deque
H, W, K = map(int, input().split())
sh, sw, gh, gw = map(int, input().split())
c = ["@" * (W+2)] + ["@" + input() + "@" for _ in range(H)] + ["@" * (W+2)]
INF = 10**6+5
dist = [[INF for _ in range(W+2)] for _ in range(H+2)]
dist[sh][sw] = 0
q = deque()
q.append(sh*(W+2)+sw)
DI = [1, 0, -1, 0]
DJ = [0, 1, 0, -1]
while q:
	l = q.popleft()
	i, j = l//(W+2), l%(W+2)
	for di, dj in zip(DI, DJ):
		for k in range(1, K+1):
			ii, jj = i+di*k, j+dj*k
			if c[ii][jj] == "@":
				break
			if dist[ii][jj] <= dist[i][j]:
				break
			if dist[ii][jj] > dist[i][j] + 1:
				dist[ii][jj] = dist[i][j] + 1
				if ii == gh and jj == gw:
					print(dist[ii][jj])
					sys.exit()
				q.append(ii*(W+2) + jj)
print(-1)

Buggy python submission (verdict: Time Limit Exceeded):
import sys
def input():
	return sys.stdin.readline()[:-1]
from collections import deque
H, W, K = map(int, input().split())
sh, sw, gh, gw = map(int, input().split())
c = ["@" * (W+2)] + ["@" + input() + "@" for _ in range(H)] + ["@" * (W+2)]
INF = 10**7
dist = [[INF for _ in range(W+2)] for _ in range(H+2)]
dist[sh][sw] = 0
q = deque()
q.append(sh*(W+2)+sw)
DI = [1, 0, -1, 0]
DJ = [0, 1, 0, -1]
while q:
	l = q.popleft()
	i, j = l//(W+2), l%(W+2)
	if i == gh and j == gw:
		print(dist[i][j])
		sys.exit()
	for di, dj in zip(DI, DJ):
		for k in range(1, K+1):
			ii, jj = i+di*k, j+dj*k
			if c[ii][jj] == "." and dist[ii][jj] > dist[i][j]:
				dist[ii][jj] = dist[i][j] + 1
				q.append(ii*(W+2) + jj)
			else:
				break
print(-1)

Fixed submission:
import sys
def input():
	return sys.stdin.readline()[:-1]
from collections import deque
H, W, K = map(int, input().split())
sh, sw, gh, gw = map(int, input().split())
c = ["@" * (W+2)] + ["@" + input() + "@" for _ in range(H)] + ["@" * (W+2)]
INF = 10**6+5
dist = [[INF for _ in range(W+2)] for _ in range(H+2)]
dist[sh][sw] = 0
q = deque()
q.append(sh*(W+2)+sw)
DI = [1, 0, -1, 0]
DJ = [0, 1, 0, -1]
while q:
	l = q.popleft()
	i, j = l//(W+2), l%(W+2)
	for di, dj in zip(DI, DJ):
		for k in range(1, K+1):
			ii, jj = i+di*k, j+dj*k
			if c[ii][jj] == "@":
				break
			if dist[ii][jj] <= dist[i][j]:
				break
			if dist[ii][jj] > dist[i][j] + 1:
				dist[ii][jj] = dist[i][j] + 1
				if ii == gh and jj == gw:
					print(dist[ii][jj])
					sys.exit()
				q.append(ii*(W+2) + jj)
print(-1)

Buggy python submission (verdict: Time Limit Exceeded):
import sys
def input():
	return sys.stdin.readline()[:-1]
from collections import deque
H, W, K = map(int, input().split())
sh, sw, gh, gw = map(int, input().split())
c = ["@" * (W+2)] + ["@" + input() + "@" for _ in range(H)] + ["@" * (W+2)]
INF = 10**7
dist = [[INF for _ in range(W+2)] for _ in range(H+2)]
dist[sh][sw] = 0
q = deque()
q.append(sh*(W+2)+sw)
DI = [1, 0, -1, 0]
DJ = [0, 1, 0, -1]
while q:
	l = q.popleft()
	i, j = l//(W+2), l%(W+2)
	if i == gh and j == gw:
		print(dist[i][j])
		sys.exit()
	for di, dj in zip(DI, DJ):
		for k in range(1, K+1):
			ii, jj = i+di*k, j+dj*k
			if c[ii][jj] == "." and dist[ii][jj] > dist[i][j]:
				dist[ii][jj] = dist[i][j] + 1
				q.append(ii*(W+2) + jj)
			else:
				break
print(-1)

Fixed submission:
import sys
def input():
	return sys.stdin.readline()[:-1]
from collections import deque
H, W, K = map(int, input().split())
sh, sw, gh, gw = map(int, input().split())
c = ["@" * (W+2)] + ["@" + input() + "@" for _ in range(H)] + ["@" * (W+2)]
INF = 10**6+5
dist = [[INF for _ in range(W+2)] for _ in range(H+2)]
dist[sh][sw] = 0
q = deque()
q.append(sh*(W+2)+sw)
DI = [1, 0, -1, 0]
DJ = [0, 1, 0, -1]
while q:
	l = q.popleft()
	i, j = l//(W+2), l%(W+2)
	for di, dj in zip(DI, DJ):
		for k in range(1, K+1):
			ii, jj = i+di*k, j+dj*k
			if c[ii][jj] == "@":
				break
			if dist[ii][jj] <= dist[i][j]:
				break
			if dist[ii][jj] > dist[i][j] + 1:
				dist[ii][jj] = dist[i][j] + 1
				if ii == gh and jj == gw:
					print(dist[ii][jj])
					sys.exit()
				q.append(ii*(W+2) + jj)
print(-1)

Buggy python submission (verdict: Time Limit Exceeded):
import sys
def input():
	return sys.stdin.readline()[:-1]
from collections import deque
H, W, K = map(int, input().split())
sh, sw, gh, gw = map(int, input().split())
c = ["@" * (W+2)] + ["@" + input() + "@" for _ in range(H)] + ["@" * (W+2)]
INF = 10**7
dist = [[INF for _ in range(W+2)] for _ in range(H+2)]
dist[sh][sw] = 0
q = deque()
q.append((sh, sw))
DI = [1, 0, -1, 0]
DJ = [0, 1, 0, -1]
while q:
	i, j = q.popleft()
	if i == gh and j == gw:
		print(dist[i][j])
		sys.exit()
	for di, dj in zip(DI, DJ):
		for k in range(1, K+1):
			ii, jj = i+di*k, j+dj*k
			if c[ii][jj] == "." and dist[ii][jj] > dist[i][j]:
				dist[ii][jj] = dist[i][j] + 1
				q.append((ii, jj))
			else:
				break
print(-1)

Fixed submission:
import sys
def input():
	return sys.stdin.readline()[:-1]
from collections import deque
H, W, K = map(int, input().split())
sh, sw, gh, gw = map(int, input().split())
c = ["@" * (W+2)] + ["@" + input() + "@" for _ in range(H)] + ["@" * (W+2)]
INF = 10**6+5
dist = [[INF for _ in range(W+2)] for _ in range(H+2)]
dist[sh][sw] = 0
q = deque()
q.append(sh*(W+2)+sw)
DI = [1, 0, -1, 0]
DJ = [0, 1, 0, -1]
while q:
	l = q.popleft()
	i, j = l//(W+2), l%(W+2)
	for di, dj in zip(DI, DJ):
		for k in range(1, K+1):
			ii, jj = i+di*k, j+dj*k
			if c[ii][jj] == "@":
				break
			if dist[ii][jj] <= dist[i][j]:
				break
			if dist[ii][jj] > dist[i][j] + 1:
				dist[ii][jj] = dist[i][j] + 1
				if ii == gh and jj == gw:
					print(dist[ii][jj])
					sys.exit()
				q.append(ii*(W+2) + jj)
print(-1)