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<cstdio>
using namespace std;
int tile(int i,int j);
char memo[22][22];
int w,h;
int ii,jj;

int main(){
  while(1){
    cin >> w >> h;
    if(w==0&&h==0)break;
    for(int i=0;i<h;i++){
      cin >> memo[i];
      for(int j=0;j<w;j++){
	if(memo[i][j]=='@'){
	  ii=i;
	  jj=j;
	}
      }
    }
    int c=tile(ii,jj);
    cout << c << endl;
  }
}

int tile(int i,int j){
  if(i>=h||j>=w||i<0||j<0)return 0;
  if(memo[i][j]=='#') return 0;
  memo[i][j]='#';
  int ret=0;
  ret+=tile(i,j-1);
  ret+=tile(i,j+1);
  ret+=tile(i-1,j);
  ret+=tile(i+1,j);
  return ret+1;
}