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<stdio.h>
#include<iostream>
#include<algorithm>

using namespace std;

char tile[30][30];
int W, H;
int ix, iy;
int cnt;
int dx[4] = { 1, 0, -1, 0 };
int dy[4] = { 0, 1, 0, -1 };

void dfs(int x, int y)
{
	tile[y][x] = '#';

	cnt++;

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

int main()
{
	while (cin >> W >> H, W + H != 0)
	{
		for (int y = 0; y < H; y++)
		{
			for (int x = 0; x < W; x++)
			{
				cin >> tile[y][x];

				if (tile[y][x]=='@')
				{
					ix = x;
					iy = y;
				}
			}
		}

		dfs(ix,iy);
		
		cout << cnt << endl;

		cnt = 0;
	
	
	}

	return 0;
}