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>

int W, H;
int sx, sy;
char map[20][20];
int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};
int cnt = 0;

void dfs(int y, int x){
  map[y][x] = '#';
  cnt++;
  for(int i=0; i < 4; i++){
    if(0 <= y + dy[i] && y + dy[i] < H && 0 <= x + dx[i] && x + dx[i]< W && map[y + dy[i]][x + dx[i]] == '.'){
      dfs(y + dy[i], x + dx[i]);
    }
  }
}



int main(void){
  while(1){
    std::cin >> W >> H;
    if(W == 0 && H == 0)  return 0;

    for(int i=0; i < H; i++){
      for(int j=0; j < W; j++){
        std::cin >> map[i][j];
        if(map[i][j] == '@'){
          sx = j; sy = i;
        }
      }
    }

    cnt = 0;
    dfs(sy, sx);

    std::cout << cnt << std::endl; 
  }
}