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>
using namespace std;
int W,H,a,b,c;
int t[20][20];
char moji;
int ty[4] = {0,1,0,-1};
int tx[4] = {1,0,-1,0};

void syokika(){
  for(int i=0;i<20;i++){
    for(int j=0;j<20;j++){
      t[i][j]=0;
    }
  }
  c=0;
}
void visit(int y,int x){
  c++;
  t[y][x]=1;
  int nx,ny;
  for(int i=0;i<4;i++){
    ny=y+ty[i];
    nx=x+tx[i];
    if(0<=ny&&ny<H&&0<=nx&&nx<W&&t[ny][nx]==0){
      visit(ny,nx);
    }
  }
}
int main(){
  while(true){
    syokika();
    cin>>W>>H;
    if(W==0&&H==0)break;
    for(int i=0;i<H;i++){
      for(int j=0;j<W;j++){
	cin>>moji;
	if(moji=='.')t[i][j]=0;
	if(moji=='@'){
	  a=i;
	  b=j;
	}
	if(moji=='#')t[i][j]=-1;
      }
    }
    visit(a,b);
    cout<<c<<endl;
  }
  return 0; 
}