#include <bits/stdc++.h>

#define rep(i, n) for (int i = 0; i < int(n); i++)
#define rrep(i, n) for (int i = int(n) - 1; i >= 0; i--)
#define reps(i, n) for (int i = 1; i <= int(n); i++)
#define rreps(i, n) for (int i = int(n); i >= 1; i--)
#define repc(i, n) for (int i = 0; i <= int(n); i++)
#define rrepc(i, n) for (int i = int(n); i >= 0; i--)
#define repi(i, a, b) for (int i = int(a); i < int(b); i++)
#define repic(i, a, b) for (int i = int(a); i <= int(b); i++)
#define each(x, y) for (auto &x : y)
#define all(a) (a).begin(), (a).end()
#define bit(b) (1ll << (b))

using namespace std;

using i32 = int;
using i64 = long long;
using u64 = unsigned long long;
using f80 = long double;
using vi32 = vector<i32>;
using vi64 = vector<i64>;
using vu64 = vector<u64>;
using vf80 = vector<f80>;
using vstr = vector<string>;

inline void yes() { cout << "Yes" << '\n'; exit(0); }
inline void no() { cout << "No" << '\n'; exit(0); }
inline i64 gcd(i64 a, i64 b) { if (min(a, b) == 0) return max(a, b); if (a % b == 0) return b; return gcd(b, a % b); }
inline i64 lcm(i64 a, i64 b) { return a / gcd(a, b) * b; }
inline u64 xorshift() { static u64 x = 88172645463325252ull; x = x ^ (x << 7); return x = x ^ (x >> 9); }
template <typename T> class pqasc : public priority_queue<T, vector<T>, greater<T>> {};
template <typename T> class pqdesc : public priority_queue<T, vector<T>, less<T>> {};
template <typename T> inline void amax(T &x, T y) { if (x < y) x = y; }
template <typename T> inline void amin(T &x, T y) { if (x > y) x = y; }
template <typename T> inline T exp(T x, i64 n, T e = 1) { T r = e; while (n > 0) { if (n & 1) r *= x; x *= x; n >>= 1; } return r; }
template <typename T> inline T bis(T ok, T ng, function<bool(T)> f, T eps = 1) { while (abs(ok - ng) > eps) { T mi = (ok + ng) / 2; (f(mi) ? ok : ng) = mi; } return ok; }
template <typename T> istream& operator>>(istream &is, vector<T> &v) { each(x, v) is >> x; return is; }
template <typename T> ostream& operator<<(ostream &os, vector<T> &v) { rep(i, v.size()) { if (i) os << ' '; os << v[i]; } return os; }
template <typename T, typename S> istream& operator>>(istream &is, pair<T, S> &p) { is >> p.first >> p.second; return is; }
template <typename T, typename S> ostream& operator<<(ostream &os, pair<T, S> &p) { os << p.first << ' ' << p.second; return os; }
void solve(); int main() { ios::sync_with_stdio(0); cin.tie(0); cout << fixed << setprecision(16); solve(); return 0; }

int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};

template <typename T>
struct Matrix {
  vector<vector<T>> v;
  int r, c;
  Matrix(int r, int c, T d) : r(r), c(c) {
    v = vector<vector<T>>(r, vector<T>(c, d));
  }
  Matrix(vector<vector<T>> v) : v(v) {
    r = v.size();
    c = v[0].size();
  }
  vector<T>& operator[](int x) {
    return v[x];
  }
  Matrix<T> operator*=(Matrix<T> that) {
    assert(c == that.r);
    auto ret = Matrix<T>(r, that.c, 0);
    rep(i, r) rep(j, that.c) rep(k, c) {
      ret[i][j] += v[i][k] * that[k][j];
    }
    return *this = ret;
  }
  Matrix<T> operator*(Matrix<T> that) {
    return *this *= that;
  }
  Matrix<T> pow(i64 n) {
    assert(r == c);
    auto e = Matrix<T>(r, c, 0);
    rep(i, r) e[i][i] = 1;
    return exp(*this, n, e);
  }
  Matrix<T> inverse() {
    assert(c == r);
    vector<vector<T>> a = v;
    auto x = Matrix<T>(r, r, 0);
    rep(i, r) x[i][i] = 1;
    rep(i, r) {
      T buf = (T) 1 / a[i][i];
      rep(j, r) {
        a[i][j] *= buf;
        x[i][j] *= buf;
      }
      rep(j, r) {
        if (i == j) continue;
        buf = a[j][i];
        rep(k, r) {
          a[j][k] -= a[i][k] * buf;
          x[j][k] -= x[i][k] * buf;
        }
      }
    }
    return x;
  }
};

void solve() {
  int R, C, T;
  cin >> R >> C >> T;
  int sx, sy, gx, gy;
  cin >> sx >> sy >> gx >> gy;
  vstr B(R);
  rep(i, R) cin >> B[i];

  Matrix<f80> mat(vector<vf80>(64, vf80(64)));

  reps(i, R - 2) reps(j, C - 2) {
    if (B[i][j] == '#') continue;
    int cnt = 0;
    rep(k, 4) {
      int x = i + dx[k];
      int y = j + dy[k];
      if (B[x][y] == '.') cnt++;
    }
    if (cnt == 0) {
      mat[(i - 1) * 8 + (j - 1)][(i - 1) * 8 + (j - 1)] = 1;
      continue;
    }
    rep(k, 4) {
      int x = i + dx[k];
      int y = j + dy[k];
      if (B[x][y] == '.') {
        mat[(i - 1) * 8 + (j - 1)][(x - 1) * 8 + (y - 1)] = 1.0 / cnt;
      }
    }
  }
  Matrix<f80> vec(vector<vf80>(1, vf80(64)));
  vec[0][(sx - 1) * 8 + (sy - 1)] = 1;
  auto ans = vec * mat.pow(T);

  cout << ans[0][(gx - 1) * 8 + (gy - 1)] << endl;
}