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 <algorithm>
#include <string>
#include <vector>
#include <queue>
using namespace std;

bool map[20][20];//true??????
int W,H,X,Y;
int ct;
const int dx[] = {1,0,-1,0};
const int dy[] = {0,1,0,-1};

bool valid(int x,int y) {
	return 0 <= x && x < W && 0 <= y && y < H && map[x][y];
}

void dfs(int x,int y) {
	map[x][y] = false;
	ct++;
	for(int i = 0;i < 4;i++) {
		if(valid(x + dx[i],y + dy[i])) dfs(x + dx[i],y + dy[i]);
	}
}

int main() {
	while(cin >> W >> H && !(W == 0 && H == 0)) {
		ct = 0;
		for(int y = 0;y < H;y++) {
			char c;
			for(int x = 0;x < W;x++) {
				cin >> c;
				map[x][y] = !(c == '#');
				if(c == '@') {
					X = x;
					Y = y;
				}
			}
		}
		dfs(X,Y);
		cout << ct << endl;
	}
}