#include <iostream>
using namespace std;

char a[22][22];
int w, h;
int yy[4] = {-1, 0, 0, 1}, xx[4] = {0, 1, -1, 0};
int solve(int y, int x){
	if(a[y][x] == '#')return 0;
	a[y][x] = '#';
	int ans = 0;
	for(int i = 0;i < 4;i++){
		ans += solve(y+yy[i], x+xx[i]);
	}
	return ans+1;
}

int main(){
	int y, x;
	while(cin >> w >> h, w){
		fill((char*)a, (char*)(a+22), '#');
		for(int i = 1;i <= h;i++)
		for(int j = 1;j <= w;j++){
			cin >> a[i][j];
			if(a[i][j] == '@'){y = i;x = j;}
		}
		cout << solve(y, x) << 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;

char a[22][22];
int w, h;
int yy[4] = {-1, 0, 0, 1}, xx[4] = {0, 1, -1, 0};
int solve(int y, int x){
	if(a[y][x] == '#')return 0;
	a[y][x] = '#';
	int ans = 0;
	for(int i = 0;i < 4;i++){
		ans += solve(y+yy[i], x+xx[i]);
	}
	return ans+1;
}

int main(){
	int y, x;
	while(cin >> w >> h, w){
		fill((char*)a, (char*)(a+22), '#');
		for(int i = 1;i <= h;i++)
		for(int j = 1;j <= w;j++){
			cin >> a[i][j];
			if(a[i][j] == '@'){y = i;x = j;}
		}
		cout << solve(y, x) << endl;
	}
	return 0;
}
```