#define _USE_MATH_DEFINES
#include <iostream>
#include <fstream>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cstring>
#include <cassert>
#include <string>
#include <vector>
#include <utility>
#include <complex>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <deque>
#include <tuple>
#include <bitset>
#include <limits>
#include <algorithm>
#include <random>
#include <complex>
#include <regex>
using namespace std;
typedef long double ld;
typedef long long ll;
typedef vector<int> vint;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<double, double> pdd;
typedef complex<ld> compd;
#define reach(i,a)	for(auto i:a)
#define rep(i,n)	for(int i=0;i<(int)n;i++)
#define REP(i,n)	for(int i=0;i<=(int)n;i++)
#define srep(i,a,n)	for(int i=a;i<(int)n;i++)
#define SREP(i,a,n)	for(int i=a;i<=(int)n;i++)
#define rrep(i,n)	for(int i=n-1;i>=0;i--)
#define RREP(i,n)	for(int i=n;i>=0;i--)
#define all(a)	(a).begin(),(a).end()
#define mp(a,b)	make_pair(a,b)
#define mt	make_tuple
#define pb	push_back
#define fst	first
#define scn second
int bitcnt(ll x) {
	x = ((x & 0xAAAAAAAAAAAAAAAA) >> 1) + (x & 0x5555555555555555);
	x = ((x & 0xCCCCCCCCCCCCCCCC) >> 2) + (x & 0x3333333333333333);
	x = ((x & 0xF0F0F0F0F0F0F0F0) >> 4) + (x & 0x0F0F0F0F0F0F0F0F);
	x = ((x & 0xFF00FF00FF00FF00) >> 8) + (x & 0x00FF00FF00FF00FF);
	x = ((x & 0xFFFF0000FFFF0000) >> 16) + (x & 0x0000FFFF0000FFFF);
	x = ((x & 0xFFFFFFFF00000000) >> 32) + (x & 0x00000000FFFFFFFF);
	return x;
}
int bitcnt(int x) {
	x = ((x & 0xAAAAAAAA) >> 1) + (x & 0x55555555);
	x = ((x & 0xCCCCCCCC) >> 2) + (x & 0x33333333);
	x = ((x & 0xF0F0F0F0) >> 4) + (x & 0x0F0F0F0F);
	x = ((x & 0xFF00FF00) >> 8) + (x & 0x00FF00FF);
	x = ((x & 0xFFFF0000) >> 16) + (x & 0x0000FFFF);
	return x;
}
ll gcd(ll a, ll b) {
	return a%b == 0 ? b : gcd(b, a%b);
}
#define debug(x)	cout<<"case #" << x << ": " << endl
#define DEBUG 0
const ll inf = 1e9;
const ll mod = 1e9 + 7;
const ld eps = 1e-7;
const int dx[] = { 1,0,-1,0,0 };
const int dy[] = { 0,1,0,-1,0 };

int r, c, t;
int sx, sy, gx, gy;
vector<string> mp;
// 確率
ld ret[10][10],tmp[10][10];
// 行先(i,j)->(k,l)の遷移確率（何ターンで移動するかは更新していく）
ld nxt[10][10][10][10], nxt2[10][10][10][10];

bool isInside(int y, int x) {
	if (y < 0 || r <= y)	return false;
	if (x < 0 || c <= x)	return false;
	return true;
}

int main() {
	cin >> r >> c >> t;
	cin >> sy >> sx;
	cin >> gy >> gx;
	mp.resize(r);
	rep(i, r)	cin >> mp[i];
	ret[sy][sx] = 1.0;
	while (t > 0) {
		// nxtの初期化
		rep(i, r)	rep(j, c){
			if (mp[i][j] == '#')	continue;
			rep(k, r)	rep(l, c)	nxt[i][j][k][l] = 0.0;
			int cnt = 0;
			rep(k, 4) {
				if (!isInside(i + dy[k], j + dx[k]))	continue;
				if (mp[i + dy[k]][j + dx[k]] == '#')	continue;
				cnt++;
			}
			if (cnt == 0)	nxt[i][j][i][j] = 1.0;
			else {
				rep(k, 4) {
					if (!isInside(i + dy[k], j + dx[k]))	continue;
					if (mp[i + dy[k]][j + dx[k]] == '#')	continue;
					nxt[i][j][i + dy[k]][j + dx[k]] = 1.0 / cnt;
				}
			}
		}
		// 最初に1ターン進める（nxtの更新はしない）
		int add = 1;
		rep(i, r)	rep(j, c) {
			if (ret[i][j] < eps)	continue;
			rep(k, 5) {
				if (!isInside(i + dy[k], j + dx[k]))	continue;
				tmp[i + dy[k]][j + dx[k]] += ret[i][j] * nxt[i][j][i + dy[k]][j + dx[k]];
			}
		}
		rep(i, r)	rep(j, c) {
			ret[i][j] = tmp[i][j];
			tmp[i][j] = 0.0;
		}

		while (t - add * 2 >= 0) {
			// nxtに沿って確率の更新
			rep(i, r)	rep(j, c){
				if (ret[i][j] < eps)	continue;
				rep(k, r)	rep(l, c) {
					tmp[k][l] += ret[i][j] * nxt[i][j][k][l];
				}
			}
			rep(i, r)	rep(j, c) {
				ret[i][j] = tmp[i][j];
				tmp[i][j] = 0.0;
			}
			add <<= 1;
			// nxtの更新
			rep(i, r)	rep(j, c) rep(k, r)	rep(l, c) {
				if (nxt[i][j][k][l] < eps)	continue;
				rep(a, r)	rep(b, c) {
					nxt2[i][j][a][b] += nxt[i][j][k][l] * nxt[k][l][a][b];
				}
			}
			rep(i, r)	rep(j, c)	rep(k, r)	rep(l, c) {
				nxt[i][j][k][l] = nxt2[i][j][k][l];
				nxt2[i][j][k][l] = 0.0;
			}
		}
		t -= add;
	}
	printf("%.15Lf\n", ret[gy][gx]+eps);
	return 0;
}