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 <utility>
#include <stack>
#include <string>
using namespace std;

typedef pair<int,int> pii;

int main(void){
	int h,w;
	stack<pii> s;
	string m[21];
	while(cin>>w>>h,w||h){
		for(int i=0;i<h;i++)cin>>m[i];
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				if(m[i][j]=='@'){
					s.push(pii(i,j));
					i=j=999;
				}
			}
		}
		int c=0;
		while(!s.empty()){
			pii a=s.top();s.pop();
			int i=a.first;
			int j=a.second;
			if(!(0<=i&&i<h&&0<=j&&j<w))continue;
			if(m[i][j]=='#')continue;
			c++;
			m[i][j]='#';
			s.push(pii(i+1,j));
			s.push(pii(i-1,j));
			s.push(pii(i,j+1));
			s.push(pii(i,j-1));
		}
		cout<<c<<endl;
	}
	return 0;
}