#include <bits/stdc++.h>

using namespace std;

using ll = long long;

const int dh[] = {1, -1, 0, 0};
const int dw[] = {0, 0, 1, -1};

double dp[2][10][10];
int cnt[10][10];

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int r, c, t;
    cin >> r >> c >> t;
    int sy, sx, gy, gx;
    cin >> sy >> sx >> gy >> gx;
    vector<string> s(r);
    for (int i = 0; i < r; i++) cin >> s[i];
    for (int h = 0; h < r; h++) {
        for (int w = 0; w < c; w++) {
            for (int j = 0; j < 4; j++) {
                int nh = h + dh[j], nw = w + dw[j];
                if (nh < 0 || nh >= r || nw < 0 || nw >= c) continue;
                cnt[h][w] += (s[nh][nw] == '.');               
            }
        }
    }
    dp[0][sy][sx] = 1;
    for (int i = 0; i < max(t, 10000); i++) {
        for (int h = 0; h < r; h++) {
            for (int w = 0; w < c; w++) {
                for (int j = 0; j < 4; j++) {
                    int nh = h + dh[j], nw = w + dw[j];
                    if (nh < 0 || nh >= r || nw < 0 || nw >= c) continue;
                    if (s[nh][nw] == '#') continue;
                    dp[(i + 1) % 2][nh][nw] += dp[i % 2][h][w] / cnt[h][w];
                }
                if (i + 1 < max(t, 10000)) dp[i % 2][h][w] = 0;
            }
        }
    }
    if (t <= 10000) cout << setprecision(10) << dp[t % 2][gy][gx] << endl;
    else {
        if ((t - 10000) % 2 == 1) cout << setprecision(10) << dp[1 - t % 2][gy][gx] << endl;
        else cout << setprecision(10) << dp[t % 2][gy][gx] << endl;
    }
    return 0;
}