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

Solution (in CPP):

Solution:
#include <iostream>

using namespace std;

#define MAX 21
 
string str[MAX];
int n,m,cnt,dx[4] = {1,0,-1,0},dy[4] = {0,1,0,-1};
 
void dfs(int x,int y){
    str[x][y] = '#';
 
    for(int i = 0 ; i < 4 ; i++){
	int nx = x + dx[i] , ny = y + dy[i];
	if(0 <= nx && nx < m && 0 <= ny && ny < n){
	    if(str[nx][ny] == '.'){
		cnt++;
		dfs(nx,ny);
	    }
	}
    }
}
 
int main(){
    while(cin >> n >> m , n + m){
	for(int i = 0 ; i < m ; i++){
	    cin >> str[i];
	}
     
	int x,y;
	for(int i = 0 ; i < n ; i++){
	    for(int j = 0 ; j < m ; j++){
		if(str[j][i] == '@'){
		    x = j;
		    y = i;
		    break;
		}
	    }
	}
	cnt = 1;
	dfs(x,y);
	cout << cnt << endl;
    }
    return 0;
}