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 <cstring>
#include <iostream>

int dxy[]={1,0,-1,0,1};
int ans=0;

char tile[21][21];
int H,W;

void dfs(int x, int y){
	if(tile[x][y]=='.'){
		ans++;
		tile[x][y]='#';
	}
	for(int i = 0; i < 4; ++i){
		int nx = dxy[i] + x, ny = y + dxy[i + 1];
		if(nx < H && nx >= 0 && ny >= 0 && ny < W){
			if(tile[nx][ny] == '.')dfs(nx, ny);
		}
	}
}

int main(){
	while(std::cin>>W>>H && W+H){
		ans = 0;
		memset(tile, '#', sizeof(tile));
		int sx,sy;
		for(int i = 0; i < H; ++i){
			for(int j = 0; j < W; ++j){
				char c;
				std::cin>>c;
				tile[i][j]=c;
				if(tile[i][j] == '@')sx = i, sy = j;
			}
		}
		tile[sx][sy] = '.';
		dfs(sx,sy);
		printf("%d\n",ans);
	}
}