grid traversal by DFS

//problem link:   https://lightoj.com/problem/guilty-prince
#include <bits/stdc++.h>
using namespace std;
#define ll long long int
const int mx = 30;
char grid[mx][mx];
bool vis[mx][mx];
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
int res = 0;
int m, n;
void dfs(int x, int y) {
  vis[x][y] = true;
  res++;
  for (int i = 0; i < 4; i++) {
    int x1 = x + dx[i];
    int y1 = y + dy[i];
    if (x1 >= 1 && x1 <= n && y1 >= 1 && y1 <= m && !vis[x1][y1] &&
        grid[x1][y1] != '#') {
      dfs(x1, y1);
    }
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int tt, k = 1;
  cin >> tt;
  while (tt--) {
    memset(vis, 0, sizeof(vis));
    res = 0;
    cin >> m >> n;
    int x = 0, y = 0;
    for (int i = 1; i <= n; i++) {
      for (int j = 1; j <= m; j++) {
        cin >> grid[i][j];
        if (grid[i][j] == '@') {
          x = i, y = j;
        }
      }
    }
    dfs(x, y);
    cout << "Case " << k++ << ": " << res << "\n";
  }
  return 0;
}