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 <cstdio>
#include <algorithm>
using namespace std;

int W,H,map[20][20];
int dx[4]={1,0,-1,0},dy[4]={0,1,0,-1};

void dfs(int x,int y) {
	map[x][y]=0;
	for(int i=0;i<4;i++) {
		int nx=x+dx[i],ny=y+dy[i];
		if(0<=nx&&nx<W&&0<=ny&&ny<H&&map[nx][ny]=='.') dfs(nx,ny);
	}
}

int main() {
	int x,y;
	while(scanf("%d %d",&W,&H),W||H) {
		getchar();
		for(int j=0;j<H;j++) {
			for(int i=0;i<W;i++) {
				map[i][j]=getchar();
				if(map[i][j]=='@') {
					map[i][j]='.';
					x=i,y=j;
				}
			}
			getchar();
		}
		dfs(x,y);
		int ans=0;
		for(int j=0;j<H;j++) {
			for(int i=0;i<W;i++) {
				ans+=!map[i][j];
			}
		}
		printf("%d\n",ans);
	}
}