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<bits/stdc++.h>

using namespace std;

int n,m;
int cnt;
int dx[4]={1,0,-1,0},dy[4]={0,1,0,-1};
char t[20][20];

void fanc(int x,int y){
	cnt++;
	int ny,nx;
	t[y][x]=',';
	for(int i=0;i<4;i++){
		ny=y+dy[i];
		nx=x+dx[i];
		if(ny>=0&&nx>=0&&ny<m&&nx<n&&t[ny][nx]=='.'){
			fanc(nx,ny);
		}
	}
}

int main(){
	
	while(1){
		
		cin >> n >> m;
		
		if(n==0) break;
		
		int nx,ny;
		for(int i=0;i<m;i++){
			for(int j=0;j<n;j++){
				cin >> t[i][j];
				if(t[i][j]=='@'){
					ny=i;nx=j;
				}
			}
		}
		cnt=0;
		fanc(nx,ny);
		cout << cnt << endl;
	}
	return 0;
}