#include <cstdio>
#include <cmath>
#include <cstring>
#include <algorithm>
using namespace std;

const int MAXN = 55;
const double INF = 10000000.0;
const int dx[4] = {-1, 1, 0, 0};
const int dy[4] = {0, 0, -1, 1};
int n, m, k, sx, sy, tx, ty;
char maze[MAXN][MAXN];
double dp[MAXN][MAXN][MAXN];

int main()
{
    int T; scanf("%d", &T);
    while (T--)
    {
        scanf("%d%d%d", &n, &m, &k);
        for (int i = 0; i < n; i++)
            scanf("%s", maze[i]);
        scanf("%d%d%d%d", &sx, &sy, &tx, &ty);
        sx--; sy--; tx--; ty--;

        for (int x = 0; x < n; x++)
        for (int y = 0; y < m; y++)
        for (int z = 0; z <= k; z++)
            dp[x][y][z] = INF;
        dp[sx][sy][0] = 0.0;
        for (int z = 0; z < k; z++)
        for (int x = 0; x < n; x++)
        for (int y = 0; y < m; y++)
        {
            if (maze[x][y] != '#')
                for (int dir = 0; dir < 4; dir++)
                {
                    int xx = x + dx[dir], yy = y + dy[dir];
                    if (0 <= xx && xx < n && 0 <= yy && yy < m && maze[xx][yy] != '#')
                    {
                        dp[xx][yy][z+1] = min(dp[xx][yy][z+1], 
                            dp[x][y][z] + 1.0 * abs(maze[xx][yy] - maze[x][y]) / (k - z));
                    }
                }
        }
        double ans = INF;
        for (int i = 0; i < k; i++)
            ans = min(ans, dp[tx][ty][i]);
        if (fabs(ans - INF) < 0.00001) printf("No Answer\n");
        else printf("%.2f\n", ans);
    }
    return 0;
}