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>
using namespace std;

int W, H;
char map[20][20];
int cnt;
int angle[][2] = {
	{-1, 0}, {0, -1}, {1, 0}, {0, 1}
};

void dfs(int x, int y)
{
	if (map[x][y] == '#' || x < 0 || y < 0 || x >= W || y >= H){
		return;
	}
	cnt++;
	map[x][y] = '#';
	
	for (int i = 0; i < 4; i++){
		dfs(x + angle[i][0], y + angle[i][1]);
	}
}

int main()
{
	int num;
	
	while (scanf("%d %d", &W, &H), W + H){
		int x;
		int y;
		memset(map, 0, sizeof(map));
		
		for (int i = 0; i < H; i++){
			for (int j = 0; j < W; j++){
				scanf(" %c", &map[j][i]);
				if (map[j][i] == '@'){
					x = j;
					y = i;
					map[j][i] = '.';
				}
			}
		}
		
		cnt = 0;
		dfs(x, y);
		
		printf("%d\n", cnt);
	}
	
	return 0;
}