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 <cstdio>
using namespace std;

int dx[] = {0,1,0,-1},dy[] = {1,0,-1,0};

int w,h,res;
char field[20][20];

void dfs(int x,int y){
	res++;
	field[x][y] = '#';
	for(int i = 0;i < 4;i++){
		int nx = x + dx[i],ny = y + dy[i];
		if(nx >= 0 && nx < h && ny >= 0 && ny < w && field[nx][ny] == '.'){
			dfs(nx,ny);
		}
	}
}

int main(){
	int x,y;
	while(cin >> w >> h,w){
		res = 0;
		getchar();
		for(int i = 0;i < h;i++){
			for(int j = 0;j < w;j++) {
				field[i][j] = getchar();
				if(field[i][j] == '@'){
					x = i;
					y = j;
				}
			}
			getchar();
		}
		dfs(x,y);
		cout << res << endl;
	}
	return 0;
}