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:
#!/usr/bin/env python3
import sys
sys.setrecursionlimit(10**8)
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return [LIST() for _ in range(n)]


INF = float("inf")
MOD = 10**9 + 7
EPS = 1e-6
KETA = 10**7


def main():
    H, W, K = MAP()
    x1, y1, x2, y2 = LIST()
    c = [[-1] + [0 if c == "." else -1 for c in input()] + [-1]
         for i in range(H)]
    c = [[-1] * (W + 2)] + c + [[-1] * (W + 2)]
    c[x1][y1] = 0

    # 0123: 上下左右
    stack = [((x1 * KETA + y1) << 2) + 0, ((x1 * KETA + y1) << 2) + 1,
             ((x1 * KETA + y1) << 2) + 2, ((x1 * KETA + y1) << 2) + 3]
    DX = (1, 0, -1, 0)
    DY = (0, 1, 0, -1)
    head = 0
    while head < len(stack):
        b = stack[head]
        head += 1
        d = b % 4
        x, y = divmod(b >> 2, KETA)
        flag = True
        a = c[x][y] + 1
        for k in range(1, K + 1):
            xx, yy = x + k * DX[d], y + k * DY[d]
            if c[xx][yy] == 0:
                stack.append(((xx * KETA + yy) << 2) + (d - 1) % 4)
                stack.append(((xx * KETA + yy) << 2) + (d + 1) % 4)
                c[xx][yy] = a
            elif c[xx][yy] != a:
                flag = False
                break
        if flag:
            stack.append(((xx * KETA + yy) << 2) + d)
        if c[x2][y2] > 0:
            print(c[x2][y2])
            return

    print(-1)
    return


if __name__ == '__main__':
    main()