#include <bits/stdc++.h>
using namespace std;

typedef long long   signed int LL;
typedef long long unsigned int LU;

#define incID(i, l, r) for(int i = (l)    ; i <  (r); i++)
#define incII(i, l, r) for(int i = (l)    ; i <= (r); i++)
#define decID(i, l, r) for(int i = (r) - 1; i >= (l); i--)
#define decII(i, l, r) for(int i = (r)    ; i >= (l); i--)
#define  inc(i, n) incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define  dec(i, n) decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)

#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define inID(v, l, r) ((l) <= (v) && (v) <  (r))

#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define PQ priority_queue

#define  ALL(v)  v.begin(),  v.end()
#define RALL(v) v.rbegin(), v.rend()
#define  FOR(it, v) for(auto it =  v.begin(); it !=  v.end(); ++it)
#define RFOR(it, v) for(auto it = v.rbegin(); it != v.rend(); ++it)

template<typename T> bool   setmin(T & a, T b) { if(b <  a) { a = b; return true; } else { return false; } }
template<typename T> bool   setmax(T & a, T b) { if(b >  a) { a = b; return true; } else { return false; } }
template<typename T> bool setmineq(T & a, T b) { if(b <= a) { a = b; return true; } else { return false; } }
template<typename T> bool setmaxeq(T & a, T b) { if(b >= a) { a = b; return true; } else { return false; } }
template<typename T> T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

// ---- ----

template<int N> void mat_prod(double a[N][N], double b[N][N], double c[N][N]) { // a = b * c;
	double d[N][N];
	inc(i, N) {
	inc(j, N) {
		d[i][j] = 0.0;
	}
	}
	
	inc(i, N) {
	inc(j, N) {
	inc(k, N) {
		d[i][j] += b[i][k] * c[k][j];
	}
	}
	}
	
	inc(i, N) {
	inc(j, N) {
		a[i][j] = d[i][j];
	}
	}
	
	return;
}

template<int N> void mat_exp(double a[N][N], double b[N][N], LL c) { // a = b ^ c;
	double t[60][N][N];
	inc(i, N) {
	inc(j, N) {
		t[0][i][j] = b[i][j];
	}
	}
	inc(i, 60 - 1) {
		mat_prod<N>(t[i + 1], t[i], t[i]);
	}
	
	inc(i, N) {
	inc(j, N) {
		a[i][j] = 0.0;
	}
	}
	inc(i, N) { a[i][i] = 1.0; }
	inc(i, 60) {
		if((c >> i) % 2 == 1) {
			mat_prod<N>(a, a, t[i]);
		}
	}
	
	return;
}

// ----

LL r, c, t, si, sj, gi, gj;
string b[10];

double a[64][64], ans[64][64];

int id(int i, int j) {
	return (c - 2) * (i - 1) + (j - 1);
}

int main() {
	cin >> r >> c >> t >> si >> sj >> gi >> gj;
	inc(i, r) { cin >> b[i]; }
	
	incID(i, 1, r - 1) {
	incID(j, 1, c - 1) {
		int di[4] = { 0, 1,  0, -1 };
		int dj[4] = { 1, 0, -1,  0 };
		int p = 0;
		inc(k, 4) {
			int ii = i + di[k];
			int jj = j + dj[k];
			p += (b[ii][jj] == '.' ? 1 : 0);
		}
		if(p == 0) { a[id(i, j)][id(i, j)] = 1.0; }
		else {
			inc(k, 4) {
				int ii = i + di[k];
				int jj = j + dj[k];
				if(ii == 0 || ii == r - 1 || jj == 0 || jj == c - 1) { continue; }
				a[id(i, j)][id(ii, jj)] = (b[ii][jj] == '.' ? 1.0 / p : 0.0);
			}
		}
	}
	}
	
	mat_exp(ans, a, t);
	
	printf("%.12f\n", ans[id(si, sj)][id(gi, gj)]);
	
	return 0;
}