/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2020.06.08 18:32:24
**/

#include "bits/stdc++.h" 
using namespace std; 
typedef long long ll;

template< class T >
struct Matrix {
    std::vector< std::vector< T > > A;
    Matrix() {}
    Matrix(size_t n, size_t m) : A(n, std::vector< T >(m, 0)) {}
    Matrix(size_t n) : A(n, std::vector< T >(n, 0)) {};
    size_t height() const {
        return (A.size());
    }
    size_t width() const {
        return (A[0].size());
    }
    inline const std::vector< T > &operator[](int k) const {
        return (A.at(k));
    }
    inline std::vector< T > &operator[](int k) {
        return (A.at(k));
    }
    static Matrix I(size_t n) {
        Matrix mat(n);
        for (int i = 0; i < n; i++) mat[i][i] = 1;
        return (mat);
    }
    Matrix &operator+=(const Matrix &B) {
        size_t n = height(), m = width();
        assert(n == B.height() && m == B.width());
        for (int i = 0; i < n; i++)
            for (int j = 0; j < m; j++)
                (*this)[i][j] += B[i][j];
        return (*this);
    }
    Matrix &operator-=(const Matrix &B) {
        size_t n = height(), m = width();
        assert(n == B.height() && m == B.width());
        for (int i = 0; i < n; i++)
            for (int j = 0; j < m; j++)
                (*this)[i][j] -= B[i][j];
        return (*this);
    }
    Matrix &operator*=(const Matrix &B) {
        size_t n = height(), m = B.width(), p = width();
        assert(p == B.height());
        std::vector< std::vector< T > > C(n, std::vector< T >(m, 0));
        for (int i = 0; i < n; i++)
            for (int j = 0; j < m; j++)
                for (int k = 0; k < p; k++)
                    C[i][j] = (C[i][j] + (*this)[i][k] * B[k][j]);
        A.swap(C);
        return (*this);
    }
    Matrix operator+(const Matrix &B) const {
        return (Matrix(*this) += B);
    }
    Matrix operator-(const Matrix &B) const {
        return (Matrix(*this) -= B);
    }
    Matrix operator*(const Matrix &B) const {
        return (Matrix(*this) *= B);
    }
    friend std::ostream &operator<<(std::ostream &os, Matrix &p) {
        size_t n = p.height(), m = p.width();
        for (int i = 0; i < n; i++) {
            os << "[";
            for (int j = 0; j < m; j++) {
                os << p[i][j] << (j + 1 == m ? "]\n" : ",");
            }
        }
        return (os);
    }
    
    T determinant() {
        Matrix B(*this);
        assert(width() == height());
        T ret = 1;
        for (int i = 0; i < width(); i++) {
            int idx = -1;
            for (int j = i; j < width(); j++) {
                if (B[j][i] != 0) idx = j;
            }
            if (idx == -1) return (0);
            if (i != idx) {
                ret *= -1;
                swap(B[i], B[idx]);
            }
            ret *= B[i][i];
            T vv = B[i][i];
            for (int j = 0; j < width(); j++) {
                B[i][j] /= vv;
            }
            for (int j = i + 1; j < width(); j++) {
                T a = B[j][i];
                for (int k = 0; k < width(); k++) {
                    B[j][k] -= B[i][k] * a;
                }
            }
        }
        return (ret);
    }
    
    
    Matrix pow(ll k) const {
        auto res = I(A.size());
        auto M = *this;
        while (k > 0) {
            if (k & 1) {
                res *= M;
            }
            M *= M;
            k >>= 1;
        }
        return res;
    }
};
int h,w;
int to_index(int x,int y) {
    return w * x + y;
}
int main() {
    int t;cin >> h >> w >> t;
    int sx,sy;cin >> sx >> sy;
    int gx,gy;cin >> gx >> gy;
    Matrix<double> mat(h*w);
    vector<string> g(h);
    for (int i = 0; i < h; i++) {
        cin >> g[i];
    }
    vector<vector<int>> dir_cnt(h,vector<int>(w,0));
    const int dx[] = {0,1,0,-1}, dy[] = {1,0,-1,0};
    for (int i = 0; i < h; i++) {
        for (int j = 0; j < w; j++) {
            if (g[i][j] == '#') continue;
            for (int k = 0; k < 4; k++) {
                int x = i + dx[k], y = j + dy[k];
                if (x >= 0 && x < h && y >= 0 && y < w && g[x][y] == '.') {
                    dir_cnt[i][j]++;
                }
            }
        }
    }
    if (dir_cnt[sx][sy] == 0 && sx == gx && sy == gy) {
        cout << 1 << endl;
        return 0;
    }
    for (int i = 0; i < h; i++) {
        for (int j = 0; j < w; j++) {
            if (g[i][j] == '#') continue;
            for (int k = 0; k < 4; k++) {
                int x = i + dx[k], y = j + dy[k];
                if (x >= 0 && x < h && y >= 0 && y < w && g[x][y] == '.') {
                    mat[to_index(i,j)][to_index(x,y)] = 1.0 / dir_cnt[x][y];
                }
            }
        }
    }
    auto ans = mat.pow(t);
    printf("%.10f\n",ans[to_index(gx,gy)][to_index(sx,sy)]);
    return 0;
}