#include <iostream>
#include <cstdio>
#include <cstring>using namespace std;int n, m, sx, sy, ans;
int pd[30][30];
char maze[30][30];int dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0};void dfs(int x, int y)
{ans++, pd[x][y] = 1;for(int i = 0; i < 4; i++){int nx = x + dx[i], ny = y + dy[i];if(nx < 0 || nx >= n || ny < 0 || ny >= m) continue;if(pd[nx][ny] == 1 || maze[nx][ny] != '.') continue;dfs(nx, ny);}
}int main()
{while(scanf("%d%d", &n, &m) != EOF){if(n == 0 && m == 0) break;int t = n;n = m, m = t;for(int i = 0; i < n; i++)scanf("%s",maze[i]);for(int i = 0; i < n; i++)for(int j = 0; j < m; j++)if(maze[i][j] == '@') sx = i, sy = j;ans = 0;memset(pd, 0, sizeof(pd));dfs(sx, sy);printf("%d\n", ans);}return 0;
}

#include <iostream>
#include <cstdio>
#include <cstring>using namespace std;int n, m, sx, sy, tx, ty, ans;
int maze[30][30];
int dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0};int dfs(int k, int x, int y)
{if(x == tx && y == ty) return k - 1;if(k > 10) return -1;int nx, ny, min = -1, res;for(int i = 0; i < 4; i++){nx = x + dx[i], ny = y + dy[i];if(nx < 0 || ny < 0 || nx > n-1 || ny > m-1 || maze[nx][ny] == 1) continue;while(1){if(nx == tx && ny == ty) return k;nx += dx[i], ny += dy[i];if(nx < 0 || ny < 0 || nx > n-1 || ny > m-1) break;if(nx == tx && ny == ty) return k;if(maze[nx][ny] == 1){maze[nx][ny] = 0;res = dfs(k + 1, nx - dx[i], ny - dy[i]);maze[nx][ny] = 1;if(min == -1) min = res;else if(res != -1 && res < min) min = res;break;}}}return min;
}int main()
{while(scanf("%d%d", &m, &n) != EOF){memset(maze, 0, sizeof(maze));if(n == 0 && m == 0) break;for(int i = 0; i < n; i++)for(int j = 0; j  < m; j++){scanf("%d", &maze[i][j]);if(maze[i][j] == 2) sx = i, sy = j, maze[i][j] = 0; if(maze[i][j] == 3) tx = i, ty = j, maze[i][j] = 0; }ans = dfs(1, sx, sy);printf("%d\n", ans);}return 0;
}

#include <iostream>
#include <cstdio>
#include <cstring>
#include <queue>using namespace std;int dt[400][400];
int dx[5] = {0, 0, 1, 0, -1}, dy[5] = {0, 1, 0, -1, 0};struct node {int x, y, t;
};int bfs()
{if(dt[0][0] == 0) return -1;if(dt[0][0] == -1 ) return 0;queue<node> q;node temp,newt;temp.x = 0, temp.y = 0, temp.t = 0;q.push(temp);while(!q.empty()){temp = q.front();q.pop();for(int i = 1; i < 5; i++){newt.x = temp.x + dx[i];newt.y = temp.y + dy[i];newt.t = temp.t + 1;if(newt.x < 0 || newt.y < 0) continue;if(dt[newt.x][newt.y] == -1) return newt.t;if(dt[newt.x][newt.y] <= newt.t) continue;q.push(newt);dt[newt.x][newt.y] = newt.t;}}return -1;
}int main()
{int m;while(scanf("%d", &m) != EOF){int x, y, t;memset(dt, -1, sizeof(dt));for(int j = 0; j < m; j++){scanf("%d%d%d", &x, &y, &t);for(int i = 0; i < 5; i++){int nx = x + dx[i], ny = y + dy[i];if(nx < 0 || ny < 0) continue;if(dt[nx][ny] == -1) dt[nx][ny] = t;else if(dt[nx][ny] > t) dt[nx][ny] = t;}}printf("%d\n",bfs());}return 0;
}