#include <iostream>
using namespace std;
int cnt,w,h;
string s[21];
void check(int i,int j){
	if(s[i][j]=='#')return;
	cnt++;
	s[i][j]='#';
	if(i>0)check(i-1,j);
	if(i<h-1)check(i+1,j);
	if(j>0)check(i,j-1);
	if(j<w-1)check(i,j+1);
}


int main(){
	while(1){
		cin >>w >>h;
		if(!(w||h))break;
		for(int i=0;i<h;i++){
			cin >>s[i];
		}
		cnt=0;
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				if(s[i][j]=='@')check(i,j);
			}
		}
	cout << cnt<<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 <iostream>
using namespace std;
int cnt,w,h;
string s[21];
void check(int i,int j){
	if(s[i][j]=='#')return;
	cnt++;
	s[i][j]='#';
	if(i>0)check(i-1,j);
	if(i<h-1)check(i+1,j);
	if(j>0)check(i,j-1);
	if(j<w-1)check(i,j+1);
}


int main(){
	while(1){
		cin >>w >>h;
		if(!(w||h))break;
		for(int i=0;i<h;i++){
			cin >>s[i];
		}
		cnt=0;
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				if(s[i][j]=='@')check(i,j);
			}
		}
	cout << cnt<<endl; 

	}
}
```