#include <iostream>
using namespace std;

int w,h,ret;
char mp[20][20];

void rec(int y,int x){
	if(mp[y][x]=='#')return;
	ret++;
	mp[y][x]='#';
	if(x+1<w)rec(y,x+1);
	if(y+1<h)rec(y+1,x);
	if(x-1>=0)rec(y,x-1);
	if(y-1>=0)rec(y-1,x);
}

int main(){
	int x,y;
	while(cin >> w >> h && w && h){
		ret = 0;
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				cin >> mp[i][j];
				if(mp[i][j]=='@'){
					y = i;
					x = j;
				}
			}
		}
		rec(y,x);
		cout << ret << endl;
	}
	return 0;
}
### Prompt

Please formulate 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>
using namespace std;

int w,h,ret;
char mp[20][20];

void rec(int y,int x){
	if(mp[y][x]=='#')return;
	ret++;
	mp[y][x]='#';
	if(x+1<w)rec(y,x+1);
	if(y+1<h)rec(y+1,x);
	if(x-1>=0)rec(y,x-1);
	if(y-1>=0)rec(y-1,x);
}

int main(){
	int x,y;
	while(cin >> w >> h && w && h){
		ret = 0;
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				cin >> mp[i][j];
				if(mp[i][j]=='@'){
					y = i;
					x = j;
				}
			}
		}
		rec(y,x);
		cout << ret << endl;
	}
	return 0;
}
```