#include <string>
#include <iostream>
using namespace std;
  
int w,h,ans,dx[]={0,-1,0,1}, dy[]={-1,0,1,0};
char c[22][22];
 
void solve(int x,int y){
    ans++;
    c[x][y]='#';
    for(int i=0;i<4;i++){
        int nx=x+dx[i], ny=y+dy[i];
        if(0<=nx && nx<w && 0<=ny && ny<h && c[nx][ny]=='.')solve(nx,ny);
    }
}
 
int main(){
    while(cin>>w>>h, w){
        ans=0;
        int x,y;
        for(int i=0;i<h;i++){
            for(int j=0; j<w; j++){
                cin>>c[j][i];
                if(c[j][i]=='@')x=j,y=i;
            }
        }
        
        solve(x,y);
        cout<<ans<<endl;
    }
}
### Prompt

In cpp, your task is to solve the following problem:

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).

Examples

Input

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


Output

45
59
6
13


Input

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


Output

45
59
6
13

### Response

```cpp
#include <string>
#include <iostream>
using namespace std;
  
int w,h,ans,dx[]={0,-1,0,1}, dy[]={-1,0,1,0};
char c[22][22];
 
void solve(int x,int y){
    ans++;
    c[x][y]='#';
    for(int i=0;i<4;i++){
        int nx=x+dx[i], ny=y+dy[i];
        if(0<=nx && nx<w && 0<=ny && ny<h && c[nx][ny]=='.')solve(nx,ny);
    }
}
 
int main(){
    while(cin>>w>>h, w){
        ans=0;
        int x,y;
        for(int i=0;i<h;i++){
            for(int j=0; j<w; j++){
                cin>>c[j][i];
                if(c[j][i]=='@')x=j,y=i;
            }
        }
        
        solve(x,y);
        cout<<ans<<endl;
    }
}
```