#include <cstring>
#include <cmath>
#include <cstdio>
#include <climits>
#include <ctime>
#include <cassert>
#include <cctype>
#include <iostream>
#include <algorithm>
#include <numeric>
#include <map>
#include <set>
#include <queue>
#include <string>
#include <vector>
#include <bitset>
#include <utility>

using namespace std;
#define all(x) (x).begin(), (x).end()
#define bit(x) (1 << (x))
#define cnt1(x) (__builtin_popcount(x))
#define LB lower_bound
#define LET(it,v) __typeof(v) it(v)
#define mset0(x) memset((x), 0, sizeof((x)))
#define mset1(x) memset((x), -1, sizeof((x)))
#define pb push_back
#define PQ priority_queue
#define REP(it,v) for(LET(it,v.begin());it!=v.end();it++)
#define sqr(x) ((x)*(x))
#define sz(x) ((int)(x.size()))
#define UB upper_bound
#define X first
#define Y second

typedef long long LL;
typedef double DB;
typedef pair<int, int> pii;
typedef pair<LL, LL> pll;
typedef vector<int> vi;
typedef vector<pii> vpii;

template <class T> inline void chkmin(T &a, T b) {
    if (b < a) a = b;
}
template <class T> inline void chkmax(T &a, T b) {
    if (a < b) a = b;
}

const int MX = 55;
char s[MX][MX];

int n, m;
int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};
bool in(int x, int y) {
    return (x >= 0 && x < n && y >= 0 && y < m && s[x][y] != '#');
}

const double INF = 1e15;
const double EPS = 1e-7;
double rlt[MX][MX][MX];

struct Data {
    Data(){}
    Data(int x, int y, int k, double d):x(x), y(y), k(k), d(d){}
    int x, y, k;
    double d;
};
bool operator <(const Data &a, const Data &b) {
    return a.d > b.d;
}
PQ<Data> Q;

int main() {
    
    int T;
    int K;
    int i, j, k, sx, sy, ex, ey, x, y;
    
    for (scanf("%d", &T); T--; ) {
        scanf("%d%d%d", &n, &m, &K);
        for (i = 0; i < n; i++) {
            scanf("%s", s[i]);
        }
        scanf("%d%d%d%d", &sx, &sy, &ex, &ey);
        sx--, sy--, ex--, ey--;
        
        for (i = 0; i < n; i++) {
            for (j = 0; j < m; j++) {
                for (k = 0; k <= K; k++) rlt[i][j][k] = INF;
            }
        }
        
        while (!Q.empty()) Q.pop();
        rlt[sx][sy][K] = 0;
        Q.push(Data(sx, sy, K, 0));
        
        int flg = 0;
        Data dt;
        
        while (!Q.empty()) {
            dt = Q.top();
            Q.pop();
            
            x = dt.x, y = dt.y, k = dt.k;
            if (!k) continue;
            
            if (ex == x && ey == y) {
                flg = 1;
                break;
            }
            
            if (rlt[x][y][k] < dt.d - EPS) continue;
            
            for (int d = 0; d < 4; d++) {
                int tx = x + dx[d], ty = y + dy[d];
                if (!in(tx, ty)) continue;
                
                double tp = fabs(1.0 * (s[x][y] - '0') - (s[tx][ty] - '0')) / k;
                double &ans = rlt[tx][ty][k - 1];
                if (ans < rlt[x][y][k] + tp + EPS) continue;
                
                ans = rlt[x][y][k] + tp;
                Q.push(Data(tx, ty, k - 1, ans));
            }
        }
        
        if (!flg) puts("No Answer");
        else printf("%.2lf\n", dt.d);
        
    }
    
    return 0;
}