#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using P = pair<int, int>;

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

double dp[2][10][10];
int cnt[10][10];
//bool used[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];
    /*
    used[sy][sx] = true;
    auto judge = [&](){
        stack<P> stk;
        stk.emplace(sy, sx);
        while (!stk.empty()) {
            int h = stk.top().first, w = stk.top().second;
            stk.pop();
            if (h == gy && w == gx) return true;
            used[h][w] = true;
            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;
                if (used[nh][nw]) continue;
                stk.emplace(nh, nw);
            }
        }
        return false;
    };
    if (!judge()) {
        cout << 0 << endl;
        return 0;
    }*/
    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;
    if (cnt[sy][sx] == 0) {
        cout << setprecision(10) << dp[0][gy][gx] << endl;
        return 0;
    }
    const int MAX_T = 10000;
    for (int i = 0; i < min(t, MAX_T); i++) {
        for (int h = 0; h < r; h++) {
            for (int w = 0; w < c; w++) {
                if (s[h][w] == '#') continue;
                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 < min(t, MAX_T)) dp[i % 2][h][w] = 0;
            }
        }
    }
    if (t <= MAX_T) cout << setprecision(10) << dp[t % 2][gy][gx] << endl;
    else {
        if ((t - MAX_T) % 2 == 1) cout << setprecision(10) << dp[1 - MAX_T % 2][gy][gx] << endl;
        else cout << setprecision(10) << dp[MAX_T % 2][gy][gx] << endl;
    }
    return 0;
}