#include<iostream>
#include<string>
#include<vector>
using namespace std;
#define loop(i,a,b) for(int i=a;i<b;i++)
#define rep(i,a) loop(i,0,a)
int x[4]={1,0,-1,0};
int y[4]={0,1,0,-1};
int func(int i,int j,int n,int m,vector<string>& in,int& co){
  co++;
  //cout<<co<<endl;
  in[i][j]='!';
  rep(k,4){
    int nx=i+x[k];
    int ny=j+y[k];
    if(nx>=0 && nx<=n-1 && ny>=0 && ny<=m-1 && in[nx][ny]!='!' && in[nx][ny]=='.')func(nx,ny,n,m,in,co);
  }
  return co;
}
int main(){
  int n,m;
  while(cin>>m>>n,n||m){
    vector<string>in(n);
    int co=0;
    rep(i,n)cin>>in[i];
    rep(i,n)rep(j,m)if(in[i][j]=='@')co=func(i,j,n,m,in,co);
    cout<<co<<endl;
  }
}
### Prompt

Your task is to create 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<string>
#include<vector>
using namespace std;
#define loop(i,a,b) for(int i=a;i<b;i++)
#define rep(i,a) loop(i,0,a)
int x[4]={1,0,-1,0};
int y[4]={0,1,0,-1};
int func(int i,int j,int n,int m,vector<string>& in,int& co){
  co++;
  //cout<<co<<endl;
  in[i][j]='!';
  rep(k,4){
    int nx=i+x[k];
    int ny=j+y[k];
    if(nx>=0 && nx<=n-1 && ny>=0 && ny<=m-1 && in[nx][ny]!='!' && in[nx][ny]=='.')func(nx,ny,n,m,in,co);
  }
  return co;
}
int main(){
  int n,m;
  while(cin>>m>>n,n||m){
    vector<string>in(n);
    int co=0;
    rep(i,n)cin>>in[i];
    rep(i,n)rep(j,m)if(in[i][j]=='@')co=func(i,j,n,m,in,co);
    cout<<co<<endl;
  }
}
```