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>
using namespace std;

int W, H;
const int SIZE = 20;
char f[SIZE + 1][SIZE + 1];
bool c[SIZE][SIZE];

int dfs(int x, int y){
	if(x < 0 || y < 0 || x >= W || y >= H) return 0;
	if(c[y][x] || f[y][x] == '#') return 0;
	c[y][x] = true;
	
	return 1 + dfs(x + 1, y) + dfs(x, y + 1) + dfs(x - 1, y) + dfs(x, y - 1);
}

int main(){
	int sx, sy;
	
	while(true){
		scanf("%d%d", &W, &H);
		if(H == 0 && W == 0) break;
		for(int i = 0; i < H; i++){
			scanf("%s", f[i]);
		}
		
		for(int y = 0; y < H; y++){
			for(int x = 0; x < W; x++){
				c[y][x] = false;
				if(f[y][x] == '@'){
					sx = x; sy = y;
				}
			}
		}
		
		printf("%d\n", dfs(sx, sy));
	}
	
	return 0;
}