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<cstdio>
using namespace std;
int w,h;
char m[21][21];

int dfs(int y,int x){
  if(x < 0 || x >= w)return 0;
  if(y < 0 || y >= h)return 0;
  if(m[y][x] == '#') return 0;
  int ret = 1;
  m[y][x] = '#';
  ret += dfs(y+1,x);
  ret += dfs(y-1,x);
  ret += dfs(y,x+1);
  ret += dfs(y,x-1);
  return ret;
}

int main(){
  int sx,sy;
  while(true){
  scanf("%d %d",&w,&h);
  if(w == 0 && h == 0)break;
  for(int i = 0;i < h;i++){
    scanf("%s",m[i]);
    for(int j = 0;j < w;j++){
      if(m[i][j] == '@'){
        sx=j;sy=i;
      }
    }
  }
  printf("%d\n",dfs(sy,sx));
  }
}