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 <bits/stdc++.h>
using namespace std;
bool mp[50][50];
int dx[4]={1,0,-1,0},dy[4]={0,1,0,-1};
int h,w;
int dfs(int y,int x){
  if(mp[y][x])return 0;
  int ret=1;
  mp[y][x]=1;
  for(int i=0;i<4;i++){
    int nx=x+dx[i],ny=y+dy[i];
    if(nx<0 || nx>=w || ny<0 || ny>=h) continue;
    ret+=dfs(ny,nx);
  }
  return ret;
}
  
int main(){
  string s;
  int si,sj;
  while(cin>>w>>h && w&&h){
    memset(mp,0,sizeof(mp));
    for(int i=0;i<h;i++){
      cin>>s;
      for(int j=0;j<w;j++){
        if(s[j]=='#') mp[i][j]=1;
        else if(s[j]=='@') {si=i;sj=j;}
      }
    }
    cout<<dfs(si,sj)<<endl;
  }
  return 0;
}