#include<iostream>
#include<cstdio>
using namespace std;

char map[21][21];
int tx[4] = {-1,0,1,0};
int ty[4] = {0,1,0,-1};
int w,h,c;

int search(int y,int x){
  int i,nx,ny;
  c++;
  for(i=0;i<4;i++){
    nx=x+tx[i];
    ny=y+ty[i];
    if(0<=nx && nx<w && 0<=ny && ny<h && map[ny][nx]!='#'){
      map[ny][nx]='#';
      search(ny,nx);
    }
  }
  
  return c;
  
}

int main(){

  int i,j,nx,ny;
  int a;

  while(1){
    c=0;
    cin>>w>>h;
  
    if(w==0&&h==0){
      break;
    }	    
 
    
    for(i=0; i<h ; i++){
      for(j=0; j<w ; j++){
	cin>>map[i][j];
	if(map[i][j]=='@'){
	  nx = j;
	  ny = i;
	}
      } 
    }
    
    map[ny][nx]='#';
    a=search(ny,nx);
    cout<<c<<endl;
    
  }
  return 0;
}
### Prompt

Generate a CPP solution to 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<iostream>
#include<cstdio>
using namespace std;

char map[21][21];
int tx[4] = {-1,0,1,0};
int ty[4] = {0,1,0,-1};
int w,h,c;

int search(int y,int x){
  int i,nx,ny;
  c++;
  for(i=0;i<4;i++){
    nx=x+tx[i];
    ny=y+ty[i];
    if(0<=nx && nx<w && 0<=ny && ny<h && map[ny][nx]!='#'){
      map[ny][nx]='#';
      search(ny,nx);
    }
  }
  
  return c;
  
}

int main(){

  int i,j,nx,ny;
  int a;

  while(1){
    c=0;
    cin>>w>>h;
  
    if(w==0&&h==0){
      break;
    }	    
 
    
    for(i=0; i<h ; i++){
      for(j=0; j<w ; j++){
	cin>>map[i][j];
	if(map[i][j]=='@'){
	  nx = j;
	  ny = i;
	}
      } 
    }
    
    map[ny][nx]='#';
    a=search(ny,nx);
    cout<<c<<endl;
    
  }
  return 0;
}
```