Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")


h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from heapq import heappop as hpp, heappush as hp
q = []
hp(q, (0,x1,y1,(0,0),0))

dx = [0,1,0,-1]
dy = [1,0,-1,0]
# dist = [[None]*w for _ in range(h)]
dist = [None]*(w*h)
dist[x1*w+y1] = 0
# done = [[0]*w for _ in range(h)]
done = [0]*(w*h)
done[x1*w+y1] = 15

while q:
    d, x, y, t, td = hpp(q)
    for i,(xx, yy) in enumerate(zip(dx,dy)):
        if (-xx,-yy)==t:
            continue
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w or s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
        else:
            nd = d+1
            ntd = 1
        if dist[nx*w+ny] is None or nd<dist[nx*w+ny]:
            hp(q, (nd,nx,ny,(xx,yy),ntd))
            dist[nx*w+ny] = nd
            done[nx*w+ny] = 1<<(i)
        elif nd==dist[nx*w+ny]and ((done[nx*w+ny]&1<<(i))==0):
            hp(q, (nd,nx,ny,(xx,yy),ntd))
            done[nx*w+ny] |= 1<<(i)
            
if dist[x2*w+y2] is None:
    print(-1)
else:
    print(dist[x2*w+y2])

Fixed submission:
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")

h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from queue import deque
q0 = deque([(0,x1,y1,(0,0),0)])
q1 = deque()

dx = [0,1,0,-1]
dy = [1,0,-1,0]
# dist = [[None]*w for _ in range(h)]
dist = [None]*(w*h)
dist[x1*w+y1] = 0
# done = [[0]*w for _ in range(h)]
done = [0]*(w*h)
done[x1*w+y1] = 15

while q0 or q1:
    if not q0:
        q0 = q1
        q1 = deque()
    d, x, y, t, td = q0.popleft()
    for i,(xx, yy) in enumerate(zip(dx,dy)):
        if (-xx,-yy)==t:
            continue
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w or s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
            q = q0
        else:
            nd = d+1
            ntd = 1
            q = q1
        if dist[nx*w+ny] is None or nd<dist[nx*w+ny]:
            q.append((nd,nx,ny,(xx,yy),ntd))
            dist[nx*w+ny] = nd
            done[nx*w+ny] = 1<<(i)
        elif nd==dist[nx*w+ny]and ((done[nx*w+ny]&1<<(i))==0):
            q.append((nd,nx,ny,(xx,yy),ntd))
            done[nx*w+ny] |= 1<<(i)
            
if dist[x2*w+y2] is None:
    print(-1)
else:
    print(dist[x2*w+y2])

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")


h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from heapq import heappop as hpp, heappush as hp
q = []
hp(q, (0,x1,y1,(0,0),0))

dx = [0,1,0,-1]
dy = [1,0,-1,0]
dist = [[None]*w for _ in range(h)]
dist[x1][y1] = 0
done = [[0]*w for _ in range(h)]
done[x1][y1] = 15

while q:
    d, x, y, t, td = hpp(q)
    for i,(xx, yy) in enumerate(zip(dx,dy)):
        if (-xx,-yy)==t:
            continue
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w or s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
        else:
            nd = d+1
            ntd = 1
        if dist[nx][ny] is None or nd<dist[nx][ny]:
            hp(q, (nd,nx,ny,(xx,yy),ntd))
            dist[nx][ny] = nd
            done[nx][ny] = 1<<(i)
        elif nd==dist[nx][ny]and ((done[nx][ny]&1<<(i))==0):
            hp(q, (nd,nx,ny,(xx,yy),ntd))
            done[nx][ny] |= 1<<(i)
            
if dist[x2][y2] is None:
    print(-1)
else:
    print(dist[x2][y2])

Fixed submission:
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")

h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from queue import deque
q0 = deque([(0,x1,y1,(0,0),0)])
q1 = deque()

dx = [0,1,0,-1]
dy = [1,0,-1,0]
# dist = [[None]*w for _ in range(h)]
dist = [None]*(w*h)
dist[x1*w+y1] = 0
# done = [[0]*w for _ in range(h)]
done = [0]*(w*h)
done[x1*w+y1] = 15

while q0 or q1:
    if not q0:
        q0 = q1
        q1 = deque()
    d, x, y, t, td = q0.popleft()
    for i,(xx, yy) in enumerate(zip(dx,dy)):
        if (-xx,-yy)==t:
            continue
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w or s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
            q = q0
        else:
            nd = d+1
            ntd = 1
            q = q1
        if dist[nx*w+ny] is None or nd<dist[nx*w+ny]:
            q.append((nd,nx,ny,(xx,yy),ntd))
            dist[nx*w+ny] = nd
            done[nx*w+ny] = 1<<(i)
        elif nd==dist[nx*w+ny]and ((done[nx*w+ny]&1<<(i))==0):
            q.append((nd,nx,ny,(xx,yy),ntd))
            done[nx*w+ny] |= 1<<(i)
            
if dist[x2*w+y2] is None:
    print(-1)
else:
    print(dist[x2*w+y2])

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")


h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from heapq import heappop as hpp, heappush as hp
q = []
hp(q, (0,x1,y1,(0,0),0))

dx = [0,1,0,-1]
dy = [1,0,-1,0]
dist = [[None]*w for _ in range(h)]
dist[x1][y1] = 0
done = [[0]*w for _ in range(h)]
done[x1][y1] = 15

while q:
    d, x, y, t, td = hpp(q)
    for i,(xx, yy) in enumerate(zip(dx,dy)):
        if (-xx,-yy)==t:
            continue
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w:
            continue
        if s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
        else:
            nd = d+1
            ntd = 1
        if dist[nx][ny] is None or nd<dist[nx][ny]:
            hp(q, (nd,nx,ny,(xx,yy),ntd))
            dist[nx][ny] = nd
            done[nx][ny] = 1<<(i)
        elif nd==dist[nx][ny]and ((done[nx][ny]&1<<(i))==0):
            hp(q, (nd,nx,ny,(xx,yy),ntd))
            done[nx][ny] |= 1<<(i)
            
if dist[x2][y2] is None:
    print(-1)
else:
    print(dist[x2][y2])

Fixed submission:
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")

h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from queue import deque
q0 = deque([(0,x1,y1,(0,0),0)])
q1 = deque()

dx = [0,1,0,-1]
dy = [1,0,-1,0]
# dist = [[None]*w for _ in range(h)]
dist = [None]*(w*h)
dist[x1*w+y1] = 0
# done = [[0]*w for _ in range(h)]
done = [0]*(w*h)
done[x1*w+y1] = 15

while q0 or q1:
    if not q0:
        q0 = q1
        q1 = deque()
    d, x, y, t, td = q0.popleft()
    for i,(xx, yy) in enumerate(zip(dx,dy)):
        if (-xx,-yy)==t:
            continue
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w or s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
            q = q0
        else:
            nd = d+1
            ntd = 1
            q = q1
        if dist[nx*w+ny] is None or nd<dist[nx*w+ny]:
            q.append((nd,nx,ny,(xx,yy),ntd))
            dist[nx*w+ny] = nd
            done[nx*w+ny] = 1<<(i)
        elif nd==dist[nx*w+ny]and ((done[nx*w+ny]&1<<(i))==0):
            q.append((nd,nx,ny,(xx,yy),ntd))
            done[nx*w+ny] |= 1<<(i)
            
if dist[x2*w+y2] is None:
    print(-1)
else:
    print(dist[x2*w+y2])

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")


h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from heapq import heappop as hpp, heappush as hp
q = []
hp(q, (0,x1,y1,(0,0),0))

dx = [0,1,0,-1]
dy = [1,0,-1,0]
dist = [[None]*w for _ in range(h)]
dist[x1][y1] = 0
done = [[0]*w for _ in range(h)]
done[0][0] = 15

while q:
    d, x, y, t, td = hpp(q)
    for i,(xx, yy) in enumerate(zip(dx,dy)):
        if (-xx,-yy)==t:
            continue
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w:
            continue
        if s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
        else:
            nd = d+1
            ntd = 1
        if dist[nx][ny] is None or nd<dist[nx][ny]:
            hp(q, (nd,nx,ny,(xx,yy),ntd))
            dist[nx][ny] = nd
            done[nx][ny] = 1<<(i+1)
        elif (nd==dist[nx][ny]and ((done[nx][ny]&1<<(i+1))==0)):
            hp(q, (nd,nx,ny,(xx,yy),ntd))
            done[nx][ny] |= 1<<(i+1)
            
if dist[x2][y2] is None:
    print(-1)
else:
    print(dist[x2][y2])

Fixed submission:
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")

h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from queue import deque
q0 = deque([(0,x1,y1,(0,0),0)])
q1 = deque()

dx = [0,1,0,-1]
dy = [1,0,-1,0]
# dist = [[None]*w for _ in range(h)]
dist = [None]*(w*h)
dist[x1*w+y1] = 0
# done = [[0]*w for _ in range(h)]
done = [0]*(w*h)
done[x1*w+y1] = 15

while q0 or q1:
    if not q0:
        q0 = q1
        q1 = deque()
    d, x, y, t, td = q0.popleft()
    for i,(xx, yy) in enumerate(zip(dx,dy)):
        if (-xx,-yy)==t:
            continue
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w or s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
            q = q0
        else:
            nd = d+1
            ntd = 1
            q = q1
        if dist[nx*w+ny] is None or nd<dist[nx*w+ny]:
            q.append((nd,nx,ny,(xx,yy),ntd))
            dist[nx*w+ny] = nd
            done[nx*w+ny] = 1<<(i)
        elif nd==dist[nx*w+ny]and ((done[nx*w+ny]&1<<(i))==0):
            q.append((nd,nx,ny,(xx,yy),ntd))
            done[nx*w+ny] |= 1<<(i)
            
if dist[x2*w+y2] is None:
    print(-1)
else:
    print(dist[x2*w+y2])

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")

h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from heapq import heappop as hpp, heappush as hp
q = []
hp(q, (0,x1,y1,(0,0),0))

dx = [0,1,0,-1]
dy = [1,0,-1,0]
dist = [[None]*w for _ in range(h)]
dist[x1][y1] = 0

while q:
    d, x, y, t, td = hpp(q)
    for xx, yy in zip(dx,dy):
        if (-xx,-yy)==t:
            continue
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w:
            continue
        if s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
        else:
            nd = d+1
            ntd = 1
        if dist[nx][ny] is None or nd<=dist[nx][ny]:
            hp(q, (nd,nx,ny,(xx,yy),ntd))
            dist[nx][ny] = nd
if dist[x2][y2] is None:
    print(-1)
else:
    print(dist[x2][y2])

Fixed submission:
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")

h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from queue import deque
q0 = deque([(0,x1,y1,(0,0),0)])
q1 = deque()

dx = [0,1,0,-1]
dy = [1,0,-1,0]
# dist = [[None]*w for _ in range(h)]
dist = [None]*(w*h)
dist[x1*w+y1] = 0
# done = [[0]*w for _ in range(h)]
done = [0]*(w*h)
done[x1*w+y1] = 15

while q0 or q1:
    if not q0:
        q0 = q1
        q1 = deque()
    d, x, y, t, td = q0.popleft()
    for i,(xx, yy) in enumerate(zip(dx,dy)):
        if (-xx,-yy)==t:
            continue
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w or s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
            q = q0
        else:
            nd = d+1
            ntd = 1
            q = q1
        if dist[nx*w+ny] is None or nd<dist[nx*w+ny]:
            q.append((nd,nx,ny,(xx,yy),ntd))
            dist[nx*w+ny] = nd
            done[nx*w+ny] = 1<<(i)
        elif nd==dist[nx*w+ny]and ((done[nx*w+ny]&1<<(i))==0):
            q.append((nd,nx,ny,(xx,yy),ntd))
            done[nx*w+ny] |= 1<<(i)
            
if dist[x2*w+y2] is None:
    print(-1)
else:
    print(dist[x2*w+y2])

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")


h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from heapq import heappop as hpp, heappush as hp
q = []
hp(q, (0,x1,y1,(0,0),0))

dx = [0,1,0,-1]
dy = [1,0,-1,0]
dist = [[float("inf")]*w for _ in range(h)]
dist[x1][y1] = 0

while q:
    d, x, y, t, td = hpp(q)
    for xx, yy in zip(dx,dy):
        if (-xx,-yy)==t:
            continue
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w:
            continue
        if s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
        else:
            nd = d+1
            ntd = 1
        if nd<=dist[nx][ny]:
            hp(q, (nd,nx,ny,(xx,yy),ntd))
            dist[nx][ny] = nd
if dist[x2][y2] >10**10:
    print(-1)
else:
    print(dist[x2][y2])

Fixed submission:
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")

h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from queue import deque
q0 = deque([(0,x1,y1,(0,0),0)])
q1 = deque()

dx = [0,1,0,-1]
dy = [1,0,-1,0]
# dist = [[None]*w for _ in range(h)]
dist = [None]*(w*h)
dist[x1*w+y1] = 0
# done = [[0]*w for _ in range(h)]
done = [0]*(w*h)
done[x1*w+y1] = 15

while q0 or q1:
    if not q0:
        q0 = q1
        q1 = deque()
    d, x, y, t, td = q0.popleft()
    for i,(xx, yy) in enumerate(zip(dx,dy)):
        if (-xx,-yy)==t:
            continue
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w or s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
            q = q0
        else:
            nd = d+1
            ntd = 1
            q = q1
        if dist[nx*w+ny] is None or nd<dist[nx*w+ny]:
            q.append((nd,nx,ny,(xx,yy),ntd))
            dist[nx*w+ny] = nd
            done[nx*w+ny] = 1<<(i)
        elif nd==dist[nx*w+ny]and ((done[nx*w+ny]&1<<(i))==0):
            q.append((nd,nx,ny,(xx,yy),ntd))
            done[nx*w+ny] |= 1<<(i)
            
if dist[x2*w+y2] is None:
    print(-1)
else:
    print(dist[x2*w+y2])

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")


h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from queue import deque
q = deque([(x1,y1,0,(0,0),0)])
dx = [0,1,0,-1]
dy = [1,0,-1,0]
dist = [[float("inf")]*w for _ in range(h)]
dist[x1][y1] = 0
while q:
    x, y, d, t, td = q.popleft()
    for xx, yy in zip(dx,dy):
        if (-xx,-yy)==t:
            continue
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w:
            continue
        if s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
        else:
            nd = d+1
            ntd = 1
        if nd<=dist[nx][ny]:
            q.append((nx,ny,nd,(xx,yy),ntd))
            dist[nx][ny] = nd
if dist[x2][y2] >10**10:
    print(-1)
else:
    print(dist[x2][y2])

Fixed submission:
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")

h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from queue import deque
q0 = deque([(0,x1,y1,(0,0),0)])
q1 = deque()

dx = [0,1,0,-1]
dy = [1,0,-1,0]
# dist = [[None]*w for _ in range(h)]
dist = [None]*(w*h)
dist[x1*w+y1] = 0
# done = [[0]*w for _ in range(h)]
done = [0]*(w*h)
done[x1*w+y1] = 15

while q0 or q1:
    if not q0:
        q0 = q1
        q1 = deque()
    d, x, y, t, td = q0.popleft()
    for i,(xx, yy) in enumerate(zip(dx,dy)):
        if (-xx,-yy)==t:
            continue
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w or s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
            q = q0
        else:
            nd = d+1
            ntd = 1
            q = q1
        if dist[nx*w+ny] is None or nd<dist[nx*w+ny]:
            q.append((nd,nx,ny,(xx,yy),ntd))
            dist[nx*w+ny] = nd
            done[nx*w+ny] = 1<<(i)
        elif nd==dist[nx*w+ny]and ((done[nx*w+ny]&1<<(i))==0):
            q.append((nd,nx,ny,(xx,yy),ntd))
            done[nx*w+ny] |= 1<<(i)
            
if dist[x2*w+y2] is None:
    print(-1)
else:
    print(dist[x2*w+y2])

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")


h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from queue import deque
q = deque([(x1,y1,0,(0,0),0)])
dx = [0,1,0,-1]
dy = [1,0,-1,0]
dist = [[float("inf")]*w for _ in range(h)]
dist[x1][y1] = 0
while q:
    x, y, d, t, td = q.popleft()
    for xx, yy in zip(dx,dy):
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w:
            continue
        if s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
        else:
            nd = d+1
            ntd = 1
        if nd<=dist[nx][ny]:
            q.append((nx,ny,nd,(xx,yy),ntd))
            dist[nx][ny] = nd
if dist[x2][y2] >10**10:
    print(-1)
else:
    print(dist[x2][y2])

Fixed submission:
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")

h,w,k = map(int, input().split())
x1,y1,x2,y2 = map(lambda x: int(x)-1, input().split())
s = [None]*h
for i in range(h):
    s[i] = input()
    
from queue import deque
q0 = deque([(0,x1,y1,(0,0),0)])
q1 = deque()

dx = [0,1,0,-1]
dy = [1,0,-1,0]
# dist = [[None]*w for _ in range(h)]
dist = [None]*(w*h)
dist[x1*w+y1] = 0
# done = [[0]*w for _ in range(h)]
done = [0]*(w*h)
done[x1*w+y1] = 15

while q0 or q1:
    if not q0:
        q0 = q1
        q1 = deque()
    d, x, y, t, td = q0.popleft()
    for i,(xx, yy) in enumerate(zip(dx,dy)):
        if (-xx,-yy)==t:
            continue
        nx, ny = xx+x, yy+y
        if nx<0 or nx>=h or ny<0 or ny>=w or s[nx][ny]=="@":
            continue
        if (xx,yy)==t and td<k:
            nd = d
            ntd = td+1
            q = q0
        else:
            nd = d+1
            ntd = 1
            q = q1
        if dist[nx*w+ny] is None or nd<dist[nx*w+ny]:
            q.append((nd,nx,ny,(xx,yy),ntd))
            dist[nx*w+ny] = nd
            done[nx*w+ny] = 1<<(i)
        elif nd==dist[nx*w+ny]and ((done[nx*w+ny]&1<<(i))==0):
            q.append((nd,nx,ny,(xx,yy),ntd))
            done[nx*w+ny] |= 1<<(i)
            
if dist[x2*w+y2] is None:
    print(-1)
else:
    print(dist[x2*w+y2])