#include <bits/stdc++.h>
using namespace std;
int w,h;
char a[100][100];
int dfs(int i,int j){
    if(i==h||j==w||i<0||j<0)return 0;
    if(a[i][j]=='#')return 0;
    int s=1;
    a[i][j]='#';
    s+=dfs(i+1,j);
    s+=dfs(i-1,j);
    s+=dfs(i,j+1);
    s+=dfs(i,j-1);
    return s;
}
int main(){
    int i,j;
    while(cin>>w>>h,w!=0&&h!=0){
    //char a[h][w];
    for(i=0;i<h;i++)cin>>a[i];
    for(i=0;i<h;i++)for(j=0;j<w;j++)if(a[i][j]=='@')cout<<dfs(i,j)<<endl;
}}
### Prompt

Create a solution in CPP for 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;
int w,h;
char a[100][100];
int dfs(int i,int j){
    if(i==h||j==w||i<0||j<0)return 0;
    if(a[i][j]=='#')return 0;
    int s=1;
    a[i][j]='#';
    s+=dfs(i+1,j);
    s+=dfs(i-1,j);
    s+=dfs(i,j+1);
    s+=dfs(i,j-1);
    return s;
}
int main(){
    int i,j;
    while(cin>>w>>h,w!=0&&h!=0){
    //char a[h][w];
    for(i=0;i<h;i++)cin>>a[i];
    for(i=0;i<h;i++)for(j=0;j<w;j++)if(a[i][j]=='@')cout<<dfs(i,j)<<endl;
}}
```