#include<iostream>
using namespace std;

string map[21];
int sx,sy,ans,x,y;

void search(int xx,int yy){
	ans++;
	map[yy][xx]='#';
	if(xx<x-1&&map[yy][xx+1]=='.')search(xx+1,yy);
	if(xx>0&&map[yy][xx-1]=='.')search(xx-1,yy);
	if(yy<y-1&&map[yy+1][xx]=='.')search(xx,yy+1);
	if(yy>0&&map[yy-1][xx]=='.')search(xx,yy-1);
}

int main(){
	while(cin>>x>>y,x||y){
		ans=0;
		for(int i=0;i<y;i++)cin>>map[i];
		for(int i=0;i<y;i++){
			for(int j=0;j<x;j++){
				if(map[i][j]=='@')sy=i,sx=j;
			}
		}
		search(sx,sy);
		cout<<ans<<endl;
	}
}
### Prompt

Please provide a CPP coded solution to the problem described below:

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>
using namespace std;

string map[21];
int sx,sy,ans,x,y;

void search(int xx,int yy){
	ans++;
	map[yy][xx]='#';
	if(xx<x-1&&map[yy][xx+1]=='.')search(xx+1,yy);
	if(xx>0&&map[yy][xx-1]=='.')search(xx-1,yy);
	if(yy<y-1&&map[yy+1][xx]=='.')search(xx,yy+1);
	if(yy>0&&map[yy-1][xx]=='.')search(xx,yy-1);
}

int main(){
	while(cin>>x>>y,x||y){
		ans=0;
		for(int i=0;i<y;i++)cin>>map[i];
		for(int i=0;i<y;i++){
			for(int j=0;j<x;j++){
				if(map[i][j]=='@')sy=i,sx=j;
			}
		}
		search(sx,sy);
		cout<<ans<<endl;
	}
}
```