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 CPP):

Solution:
#include <iostream>
#include <string>
#include <sstream>
#include <iomanip> 
#include <math.h>
#include <stdio.h>
#include <string.h>
#include <queue>
#include <stack>
#include <vector>
#include <map>
#include <set>
#include <functional>
#include <algorithm>
#include <unordered_map>
#include <unordered_set>
#include <bitset>

using namespace std;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);

	int n, m, k, i, j, kk, x1, y1, x2, y2, x, y, xx, yy, ans, INF = 10000000;

	cin >> n >> m >> kk >> x1 >> y1 >> x2 >> y2;
	vector<string> s(n);
	for (i = 0; i < n; i++) cin >> s[i];

	vector<vector<int>> dp(n + 1, vector<int>(m + 1, INF));
	dp[x1][y1] = 0;
	queue<pair<int, int>> q;
	q.push({ x1, y1 });

	int v[4][2] = { 1, 0, 0, 1, -1, 0, 0, -1 };

	while (!q.empty()) {
		x = q.front().first;
		y = q.front().second;
		q.pop();

		for (k = 0; k < 4; k++) {
			for (i = 1; i <= kk; i++) {
				xx = x + i * v[k][0];
				yy = y + i * v[k][1];
				if ((xx <= 0) || (xx > n) || (yy <= 0) || (yy > m)) break;
				if (s[xx - 1][yy - 1] == '@') break;
				if (dp[xx][yy] == dp[x][y]) break;
				if (dp[xx][yy] == INF) {
					dp[xx][yy] = dp[x][y] + 1;
					q.push({ xx, yy });
				}
			}
		}
	}

	if (dp[x2][y2] == INF) ans = -1;
	else ans = dp[x2][y2];

	cout << ans << "\n";

	return 0;
}