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;
int x[4]={0,0,1,-1};
int y[4]={1,-1,0,0};
int i,j;
int count=0;
char room[100][100];

int dfs(int, int);

int main(){
  while(1){
    int sy,sx;
    cin >> W >> H;
    if(W==0&&H==0)break;
    for(i = 0 ; i < H ; i++){
      for(j = 0 ; j < W ; j++){
	cin >> room[i][j];
	if(room[i][j] == '@'){
	  sy = i;
	  sx = j; 
	}
      }
    }
    cout << dfs(sx,sy) << endl;
  }
  return 0;
}

int dfs(int ax,int ay){
  if(ax<0||ay<0)return 0;
  if(ax>=W||ay>=H)return 0;
  if(room[ay][ax]=='#')return 0;
  room[ay][ax]='#';
  int cnt=1;
  int i;
  for(i=0;i<4;i++){
    int nx=ax+x[i];
    int ny=ay+y[i];
    cnt+=dfs(nx,ny);
  }
  return cnt;
}