#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <complex>
#include <map>
#include <set>
#include <vector>
#include <stack>
#include <queue>
#include <bitset>
#include <algorithm>
#include <numeric>
#include <functional>
using namespace std;

#define Rep(b, e, i) for(int i = b; i <= e; i++)
#define Repr(e, b, i) for(int i = e; i >= b; i--)
#define rep(n, i) Rep(0, n-1, i)
#define repr(n, i) Repr(n-1, 0, i)
#define all(v) (v).begin(), (v).end()
#define pb(v) push_back(v)
#define uniq(v) (v).erase(unique(all(v)),(v).end())
#define bitcnt(x) __builtin_popcount(x)
#define fst first
#define snd second
#define Pqaz(T) priority_queue<T,vector<T>,greater<T>>
#define Pqza(T) priority_queue<T>
#define put(x) cout << x;
#define puts(x) cout << x << ' ';
#define putln(x) cout << x << endl;
#define ENJYU std::ios::sync_with_stdio(false);std::cin.tie(0);

typedef long long ll;
typedef pair<ll, ll> llP;
typedef pair<int, int> intP;
typedef complex<double> comp;

//vector の中身を出力
template <class T>ostream &operator<<(ostream &o,const vector<T>&v)
{o<<"{";for(int i=0;i<(int)v.size();i++)o<<(i>0?", ":"")<<v[i];o<<"}";return o;}

const int MAX = 100000;

int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};

double dp[MAX][10][10];

void solve(void){
	int R, C, T;
	cin >> R >> C >> T;

	int sx, sy, gx, gy;
	cin >> sy >> sx >> gy >> gx;

	vector <double> dp(10*10, 0.), now;
	now = dp;

	now[sy*10+sx] = 1;

	vector <string> maze(R);
	rep(R, i) cin >> maze[i];

	if (MAX < T)
	{
		if (T & 1)
		{
			T = MAX-1;
		}
		else
		{
			T = MAX;
		}
	}

	while(T--)
	{
		fill(all(dp), 0);

		rep(R, r) rep(C, c)
		{
			if (maze[r][c] == '#')
			{
				continue;
			}

			int nbcnt = 0;

			rep(4, i)
			{
				int nr = r + dy[i], nc = c + dx[i];

				if (0 <= nr && nr < R && 0 <= nc && nc < C)
				{
					nbcnt += maze[nr][nc] == '.';
				}

			}

			if (nbcnt == 0)
			{
				dp[r*10+c] = now[r*10+c];
				continue;
			}

			double p = 1. / nbcnt;

			rep(4, i)
			{
				int nr = r + dy[i], nc = c + dx[i];

				if (0 <= nr && nr < R && 0 <= nc && nc < C)
				{
					if (maze[nr][nc] == '.')
					{
						dp[nr*10+nc] += now[r*10+c] * p;
					}
				}

			}

		}

		now = dp;

	}

	printf("%.12lf\n", now[gy*10+gx]);

}

int main(void){
	solve();
	//cout << "yui(*-v・)yui" << endl;
	return 0;
}