1 /*
 2     Name: hdu--1312--Red and Black 
 3     Copyright:  ?2017 日天大帝
 4     Author: 日天大帝
 5     Date: 30/04/17 19:19
 6     Description: dfs
 7 */
 8 #include<iostream>
 9 #include<cstring> 
10 using namespace std;
11 void dfs(int,int);
12 char map[30][30];
13 int w,h,ans;
14 int x,y;
15 int dir[4][2] = {0,1,0,-1,1,0,-1,0};
16 int main(){
17     ios::sync_with_stdio(false);
18 
19     while(cin>>w>>h,w||h){
20         memset(map,0,sizeof(map));
21         ans = 0;
22         for(int i=0; i<h; ++i){
23             cin>>map[i];
24             for(int j=0; j<w; ++j){
25                 if(map[i][j] == ‘@‘){
26                     x = i;y = j;
27                 }
28             }
29         }
30         dfs(x,y);
31         cout<<ans<<endl;
32     }
33     return 0;
34 }
35 void dfs(int x,int y){
36     ans++;
37     for(int i=0; i<4; ++i){
38         int xx = x + dir[i][0];
39         int yy = y + dir[i][1];
40         if(xx<0 || yy<0 ||xx >=h|| yy>=w|| map[xx][yy] != ‘.‘)continue;
41         map[xx][yy] = ‘#‘;
42         dfs(xx,yy);
43     }
44 }