//  {{{

#include <bits/stdc++.h>
using namespace std;

#ifndef ONLINE_JUDGE
#include "debug.cpp"
#else
#define debug(...)
#define debugArr(...)
#endif

using ll = long long;

const int inf = 1073741823;
const ll infl = 1LL << 60;

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

#define rep(i, b) for (auto i = 0; i < (b); i++)
#define reps(i, b) for (auto i = 1; i <= (b); i++)
#define maxn 100005
int fx[] = {-1, 1, 0, 0};
int fy[] = {0, 0, -1, 1};

// }}}

int n,m,r,c,x1,Y1,x2,y2;
    vector<vector<int>> vis, dis;
    bool valid(int x, int y)
    {
        if(x >= 0 and x < n and y >= 0 and y < m and !vis[x][y]) return true;
        else return false;
    }

    void bfs(int sx, int sy, vector<vector<int>>& grid)
    {
        vis[sx][sy] = 1;
        dis[sx][sy] = 0;
        deque<pair<int,int>> q;
        q.push_front({sx, sy});
        while(!q.empty()) {
            pair<int,int> top = q.front();
            int x = top.first;
            int y = top.second;
            q.pop_front();
            for(int k=0; k<4; k++) {
                int tx = x + fx[k];
                int ty = y + fy[k];
                if(valid(tx, ty)) {
                    vis[tx][ty] = 1;
                    if(grid[tx][ty] == 1) {
                        dis[tx][ty] = dis[x][y] + 1;
                        q.push_back({tx, ty});
                    }
                    else {
                        dis[tx][ty] = dis[x][y];
                        q.push_front({tx, ty});
                    }
                }
            }
        }
    }

    int subtask1(vector<vector<int>>& grid) {
        n = grid.size(), m = grid[0].size();
        vector<int> v;
        for(int j=0; j<m; j++) v.push_back(0);
        for(int i=0; i<n; i++) {
            vis.push_back(v);
            dis.push_back(v);
        }

        bfs(x1, Y1, grid);

        int ans = dis[x2][y2];
        return ans;
    }


int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin >> r >> c >> n;
    vector<vector<int>> mat(r, vector<int>(c));
    //int x1, Y1, x2, y2;
    cin >> x1 >> Y1 >> x2 >> y2;
    //printf("%d%d",&x1,&Y1);
    //printf("%d%d",&x2,&y2);
    --x1, --Y1, --x2, --y2;
    //cin >> x1;
    rep(i,r){
        rep(j,c){
            char inp;
            cin >> inp;
            //scanf("%c",&inp);
            if(inp=='#')mat[i][j]=1;
            else mat[i][j] = 0;
        }
    }
    //debug(mat);
    if(n==1){
        n=r, m=c;
        cout << subtask1(mat) << "\n";
        return 0;
    }
    cout << "h";
}