#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
#define rep(i,n) for(ll i=0;i<(n);i++)
char maze[20][20];
bool reached[20][20];
ll w,h;
void search(ll x,ll y){
  if(x<0 || w<=x || y<0 || h<=y) return;
  if(maze[y][x]=='#') return;
  if(reached[y][x]) return;
  reached[y][x]=true;
  search(x-1,y);
  search(x+1,y);
  search(x,y-1);
  search(x,y+1);
}
int main(){
  while(1){
    cin>>w>>h;
    if(w==0 && h==0) break;
    rep(i,h) rep(j,w) reached[i][j]=false;
    ll sx,sy;
    rep(i,h) rep(j,w) cin>>maze[i][j];
    rep(i,h) rep(j,w){
      if(maze[i][j]=='@'){
        sx=j;
        sy=i;
      }
    }
    search(sx,sy);
    ll ans=0;
    rep(i,h) rep(j,w) if(reached[i][j]) ans++;
    cout<<ans<<endl;
  }
}

### Prompt

Please create a solution in cpp 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 <bits/stdc++.h>
using namespace std;
typedef long long int ll;
#define rep(i,n) for(ll i=0;i<(n);i++)
char maze[20][20];
bool reached[20][20];
ll w,h;
void search(ll x,ll y){
  if(x<0 || w<=x || y<0 || h<=y) return;
  if(maze[y][x]=='#') return;
  if(reached[y][x]) return;
  reached[y][x]=true;
  search(x-1,y);
  search(x+1,y);
  search(x,y-1);
  search(x,y+1);
}
int main(){
  while(1){
    cin>>w>>h;
    if(w==0 && h==0) break;
    rep(i,h) rep(j,w) reached[i][j]=false;
    ll sx,sy;
    rep(i,h) rep(j,w) cin>>maze[i][j];
    rep(i,h) rep(j,w){
      if(maze[i][j]=='@'){
        sx=j;
        sy=i;
      }
    }
    search(sx,sy);
    ll ans=0;
    rep(i,h) rep(j,w) if(reached[i][j]) ans++;
    cout<<ans<<endl;
  }
}

```