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>
using namespace std;

int w, h;
char tile[21][21];

const int mx[] = {0, 0, 1, -1};
const int my[] = {1, -1, 0, 0};

int func(int x, int y){
	if(x < 0 || x >= w || y < 0 || y >= h || tile[y][x] == '#'){
		return 0;
	}
	int res = 1;
	tile[y][x] = '#';
	for(int i = 0; i < 4; ++i){
		for(int j = 0; j < 4; ++j){
			res += func(x + mx[i], y + my[i]);
		}
	}
	return res;
}

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	
	while(cin >> w >> h && w != 0 && h != 0){
	
		int sx = 0, sy = 0;
		for(int i = 0; i < h; ++i){
			for(int j = 0; j < w; ++j){
				cin >> tile[i][j];
				if(tile[i][j] == '@'){
					sy = i;
					sx = j;
				}
			}
		}
		
		cout << func(sx, sy) << endl;
	}
	
	return 0;
}