#include <iostream>
#include <cstdio>
#include <queue>

using namespace std;

#define INF 1e9

int vx[] = {1, 0, -1, 0};
int vy[] = {0, 1, 0, -1};

char H[60][60];

double DP[60][60][60];
bool in[60][60][60];

struct s
{
    int x, y, z;

    s(int _x, int _y, int _z)
    { x = _x; y = _y; z = _z; }
};

queue<s> que;

int main()
{
    int T;
    scanf("%d", &T);

    while( T-- )
    {
        int N, M, K;
        scanf("%d %d %d", &N, &M, &K);

        fill(DP[1][1], DP[N][M]+K+1, INF);

        for(int Ni = 1; Ni <= N; Ni++)
            for(int Mi = 1; Mi <= M; Mi++)
                scanf(" %c", &H[Ni][Mi]);

        int sx, sy, ex, ey;
        scanf("%d %d %d %d", &sx, &sy, &ex, &ey);

        DP[sx][sy][K] = 0;
        que.push(s(sx, sy, K) );

        while( !que.empty() )
        {
            s p = que.front(); que.pop();
            int x = p.x, y = p.y, z = p.z;
            in[x][y][z] = false;

            if( !z ) continue;

            for(int vi = 0; vi < 4; vi++)
            {
                int nx = x+vx[vi];
                int ny = y+vy[vi];

                if( 1 > nx || nx > N ) continue;
                if( 1 > ny || ny > M ) continue;

                if( H[nx][ny] == '#' ) continue;

                if( DP[nx][ny][z-1] > DP[x][y][z]+(double)abs(H[x][y]-H[nx][ny])/z )
                {
                    DP[nx][ny][z-1] = DP[x][y][z]+(double)abs(H[x][y]-H[nx][ny])/z;
                    if( !in[nx][ny][z-1] ) in[nx][ny][z-1] = true, que.push(s(nx, ny, z-1) );
                }

            }
        }

        double mn = INF;

        for(int Ki = 1; Ki <= K; Ki++)
            mn = min(mn, DP[ex][ey][Ki]);

        if( mn == INF ) puts("No Answer");
        else printf("%.2f\n", mn);
    }
}