Description

There is a rectangular room, covered with square tiles. Each tile is colored either red or black. A man is standing on a black tile. From a tile, he can move to one of four adjacent tiles. But he can't move on red tiles, he can move only on black tiles. Write a program to count the number of black tiles which he can reach by repeating the moves described above.

 

Input

The input consists of multiple data sets. A data set starts with a line containing two positive integers W and H; W and H are the numbers of tiles in the x- and y- directions, respectively. W and H are not more than 20. There are H more lines in the data set, each of which includes W characters. Each character represents the color of a tile as follows. '.' - a black tile '#' - a red tile '@' - a man on a black tile(appears exactly once in a data set) The end of the input is indicated by a line consisting of two zeros.

 

Output

For each data set, your program should output a line which contains the number of tiles he can reach from the initial tile (including itself).

 

Sample Input

6 9....#......#..............................#@...#.#..#.11 9.#..........#.#######..#.#.....#..#.#.###.#..#.#..@#.#..#.#####.#..#.......#..#########............11 6..#..#..#....#..#..#....#..#..###..#..#..#@...#..#..#....#..#..#..7 7..#.#....#.#..###.###...@...###.###..#.#....#.#..0 0

 

Sample Output

4559613

 

Source

 

 

 

1 #include
           
             2 #include
            
              3 #include
             
               4 using namespace std; 5 #define N 26 6 int n,m; 7 char mp[N][N]; 8 int x,y; 9 int vis[N][N];10 int ans;11 int dirx[]={
         0,0,-1,1};12 int diry[]={-1,1,0,0};13 void dfs(int sx,int sy){14     for(int i=0;i<4;i++){15         int xx=sx+dirx[i];16         int yy=sy+diry[i];17         if(vis[xx][yy]) continue;18         if(mp[xx][yy]=='#') continue;19         if(xx<0 || xx>=n || yy<0 || yy>=m) continue;20         vis[xx][yy]=1;21         ans++;22         dfs(xx,yy);23     }24 }25 int main()26 {27     while(scanf("%d%d",&m,&n)==2 && n+m){28         for(int i=0;i