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<queue>
using namespace std;
int main(){
  while(1){
    int w,h,s,dx[4]={0,1,0,-1},dy[4]={1,0,-1,0},an=1;
    string mp[20];
    queue<int> t;
    cin>>w>>h;
    if(w==0)break;
    for(int i=0;i<h;i++){
      cin>>mp[i];
      for(int j=0;j<w;j++)if(mp[i][j]=='@')s=w*i+j;
    }
    t.push(s);
    while(!t.empty()){
      s=t.front();
      int x=s%w,y=s/w;
      t.pop();
      for(int i=0;i<4;i++){
	int x1=x+dx[i],y1=y+dy[i];
	if(0<=x1&&x1<w&&0<=y1&&y1<h){
	  if(mp[y1][x1]=='.'){
	    t.push(w*y1+x1);
	    mp[y1][x1]='#';
	    an++;
	  }
	}
      }
    }
    cout<<an<<endl;
  }
  return 0;
}