//#include <tourist>
#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
typedef long long ll;
typedef unsigned int uint;
typedef unsigned long long ull;
const int INF = 1e9;
const ll LINF = ll(1e18);
const int MOD = 1000000007;
const int dx[4] = {0, 1, 0, -1}, dy[4] = {-1, 0, 1, 0};
const int Dx[8] = {0, 1, 1, 1, 0, -1, -1, -1}, Dy[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
#define yes cout << "Yes" << endl
#define YES cout << "YES" << endl
#define no cout << "No" << endl
#define NO cout << "NO" << endl
#define rep(i, n) for (int i = 0; i < n; i++)
#define ALL(v) v.begin(), v.end()
#define debug(v)          \
    cout << #v << ":";    \
    for (auto x : v)      \
    {                     \
        cout << x << ' '; \
    }                     \
    cout << endl;
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;
}
//cout<<fixed<<setprecision(15);有効数字15桁
//-std=c++14
//g++ yarudake.cpp -std=c++17 -I .
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int h, w, t;
    cin >> h >> w >> t;
    int sx, sy, gx, gy;
    cin >> sx >> sy >> gx >> gy;
    vector<string> s(h);
    rep(i, h) cin >> s[i];
    vector<vector<vector<double>>> dp(32, vector<vector<double>>(h * w, vector<double>(h * w, 0)));
    rep(i, h)
    {
        rep(j, w)
        {
            int count = 0;
            if (s[i][j] == '#')
                continue;
            rep(k, 4)
            {
                int ix = i + dx[k];
                int iy = j + dy[k];
                if (ix >= h || ix < 0 || iy >= w || iy < 0)
                    continue;
                if (s[ix][iy] == '.')
                    count++;
            }
            if (count == 0)
                dp[0][i * w + j][i * w + j] = 1;
            else
            {
                rep(k, 4)
                {
                    int ix = i + dx[k];
                    int iy = j + dy[k];
                    if (ix >= h || ix < 0 || iy >= w || iy < 0)
                        continue;
                    if (s[ix][iy] == '.'){
                        dp[0][i * w + j][ix * w + iy] = double(1) / count;
                    }
                    
                }
            }
        }
    }
    /*
    rep(i,h*w){
        debug(dp[0][i]);
    }
    */
    for (int d = 1; d < 32; d++)
    {
        rep(i, h * w)
        {
            rep(j, h * w)
            {
                rep(k, h * w)
                {
                    dp[d][i][j] += dp[d - 1][i][k] * dp[d - 1][k][j];
                }
            }
        }
    }
    vector<double> ans(h * w, 0);
    ans[sx * w + sy] = 1;
    rep(d, 32)
    {
        if ((1 << d) & t)
        {
            vector<double> ans_temp(h * w, 0);
            rep(i, h * w)
            {
                rep(j, h * w)
                {
                    ans_temp[j] += ans[i] * dp[d][i][j];
                }
            }
            ans=ans_temp;
        }
    }
    cout << fixed << setprecision(15);
    cout<<ans[gx*w+gy]<<"\n";
}