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[25][25];
int cnt;
int x, y;

void dfs(int y, int x){
	tile[y][x] = '#';
	cnt++;
	int dy[4] = { 0, 1, 0, -1 };
	int dx[4] = { 1, 0, -1, 0 };
	for (int i = 0; i < 4; i++){
		int Y = y + dy[i];
		int X = x + dx[i];
		if (0 <= Y&&Y < H && 0 <= X&&X < W&&tile[Y][X] != '#'){
			dfs(Y, X);
		}
	}
}

int main(){

	while (cin >> W >> H, W != 0 && H != 0){
		for (int i = 0; i < H; i++){
			for (int j = 0; j < W; j++){
				cin >> tile[i][j];
				if (tile[i][j] == '@'){
					y = i;
					x = j;
				}
			}
		}
		dfs(y, x);
		cout << cnt << endl;
		cnt = 0;
	}

	return 0;
}