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:
//
// Created by 10034 on 2020/7/30.
//

#include <iostream>
#include <vector>
#include <string>
#include <queue>
using namespace std;
const int N=1000010;
typedef pair<int,int> PII;

int dx[4]={0,0,1,-1};
int dy[4]={1,-1,0,0};
int main(){
    int n,m,k,x1,x2,y1,y2;
    cin>>n>>m>>k;
    vector<string> g(n);
    vector<vector<int>> d(n,vector<int>(m,1e9));
    queue<PII> q;
    cin>>x1>>y1>>x2>>y2;
    x1--,y1--,x2--,y2--;
    d[x1][y1]=0;
    for(int i=0;i<n;++i){
        cin>>g[i];
    }
    q.push({x1,y1});
    while(q.size()){
        int xx=q.front().first,yy=q.front().second;
        q.pop();
        for(int i=0;i<4;++i){
            for(int j=1;j<=k;++j) {
                int nx = xx + dx[i] * j, ny = yy + dy[i] * j;
                if (nx < 0 || ny < 0 || nx >=n || ny >=m ||g[nx][ny]=='@'| d[nx][ny] <= d[xx][yy]) break;
                if(d[nx][ny]>d[xx][yy]+1) {
                    d[nx][ny] = d[xx][yy] + 1;
                    q.push({nx, ny});
                }
                if(nx==x2&&ny==y2) {
                    cout<<d[nx][ny]<<endl;
                    return 0;
                }
            }
        }
    }
    puts("-1");

    return 0;
}