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>
#include <cstring>
#include <vector>
#include <string>

using namespace std;

int W, H;
vector<string> map;
int ans;

int dx[4] = {-1, 0, 1, 0};
int dy[4] = { 0,-1, 0, 1};

void dfs(int x, int y) {
	map[y][x] = '*';
	ans++;
	
	for (int d=0; d<4; d++) {
		if (!(0 <= y + dy[d] && y + dy[d] < H && 0 <= x + dx[d] && x + dx[d] < W)) continue;
		if (map[ y + dy[d] ][ x + dx[d] ] == '.') {
			dfs(x + dx[d], y + dy[d]);
		}
	}
}

int main() {
	while (1) {
		cin >> W >> H; if (W == 0 && H == 0) break;
		map.assign(H, "");
		
		int sx, sy;
		for (int i=0; i<H; i++) {
			cin >> map[i];
			for (int j=0; j<W; j++) if (map[i][j] == '@') { sx = j; sy = i; }
		}
		
		ans = 0;
		dfs(sx, sy);
		cout << ans << endl;
	}
	
	return 0;
}