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>
#include <string>
using namespace std;
typedef pair<int,int> P;
int dx[4]={0,1,0,-1};
int dy[4]={1,0,-1,0};
string s[22];
int cnt;
void dfs(int x, int y){
	cnt++;
	s[x][y]='#';
	for(int i=0;i<4;i++){
		if(s[ x+dx[i] ][ y+dy[i] ]!='#') dfs(x+dx[i],y+dy[i]);
	}
}
int main(){
	while(true){
		int w,h,sx,sy;
		cnt=0;
		cin >> w >> h;
		if(!w) break;
		for(int i=1;i<=h;i++){
			cin >> s[i];
			s[i]="#"+s[i]+"#";
		}
		s[0]="";
		s[h+1]="";
		s[0].append(w+2,'#');
		s[h+1].append(w+2,'#');
		for(int i=1;i<h+1;i++){
			for(int j=1;j<w+1;j++){
				if(s[i][j]=='@'){sx=i;sy=j;}
			}
		}
		dfs(sx,sy);
		cout << cnt << endl;
	}
	return 0;
}