Problem: Snuke, a water strider, lives in a rectangular pond that can be seen as a grid with H east-west rows and W north-south columns. Let (i,j) be the square at the i-th row from the north and j-th column from the west.

Some of the squares have a lotus leaf on it and cannot be entered. The square (i,j) has a lotus leaf on it if c_{ij} is `@`, and it does not if c_{ij} is `.`.

In one stroke, Snuke can move between 1 and K squares (inclusive) toward one of the four directions: north, east, south, and west. The move may not pass through a square with a lotus leaf. Moving to such a square or out of the pond is also forbidden.

Find the minimum number of strokes Snuke takes to travel from the square (x_1,y_1) to (x_2,y_2). If the travel from (x_1,y_1) to (x_2,y_2) is impossible, point out that fact.

Constraints

* 1 \leq H,W,K \leq 10^6
* H \times W \leq 10^6
* 1 \leq x_1,x_2 \leq H
* 1 \leq y_1,y_2 \leq W
* x_1 \neq x_2 or y_1 \neq y_2.
* c_{i,j} is `.` or `@`.
* c_{x_1,y_1} = `.`
* c_{x_2,y_2} = `.`
* All numbers in input are integers.

Input

Input is given from Standard Input in the following format:


H W K
x_1 y_1 x_2 y_2
c_{1,1}c_{1,2} .. c_{1,W}
c_{2,1}c_{2,2} .. c_{2,W}
:
c_{H,1}c_{H,2} .. c_{H,W}


Output

Print the minimum number of strokes Snuke takes to travel from the square (x_1,y_1) to (x_2,y_2), or print `-1` if the travel is impossible.

Examples

Input

3 5 2
3 2 3 4
.....
.@..@
..@..


Output

5


Input

1 6 4
1 1 1 6
......


Output

2


Input

3 3 1
2 1 2 3
.@.
.@.
.@.


Output

-1

Solution (in PYTHON3):

Solution:
from collections import deque
def bfs(maze, visited, sy, sx, gy, gx):
    queue = deque([[sy, sx]])
    visited[sy][sx] = 0
    while queue:
      #queueには訪れた地点が入っている。そこから、4方向に移動できるか考え、queueから消す。
        y, x = queue.popleft()#queueに入っていたものを消す。
        if [y, x] == [gy, gx]:#もしゴールについていたならば、そのときの手数を出す。
            return visited[y][x]
        for j, k in ([1, 0], [-1, 0], [0, 1], [0, -1]):
          p = 0
          l = 1
          while p == 0:
              new_y, new_x = y + j * l, x + k * l 
              if (0 <= new_y < H) and (0 <= new_x < W): 
                if maze[new_y][new_x] == "@":
                  p = 1
                elif visited[new_y][new_x] == -1:#まだ来たことない点だったという条件
                  visited[new_y][new_x] = visited[y][x] + 1
                  queue.append([new_y, new_x])#新しい点を足す。
                elif visited[new_y][new_x] < visited[y][x] + 1:
                  p = 1
              else:
                p = 1
              l += 1
              if l == K + 1:
                p = 1

H, W, K = map(int, input().split())
#K = min(K, max(H, W))
x1, y1, x2, y2 = map(int, input().split())
x1, y1, x2, y2 = x1-1, y1-1, x2-1, y2-1
C = [0] * H
for i in range(H):
  C[i] = str(input())
visited = [[-1] * W for i in range(H)]
bfs(C, visited, x1, y1, x2, y2)
#print(visited)
print(visited[x2][y2])