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 <algorithm>
#include <cstring>
using namespace std;
int w,h;
char tbl[30][30];
int dx[] = {0,0,1,-1};
int dy[] = {1,-1,0,0};
bool visited[30][30];
int ans;

void dfs(int x,int y){
  visited[y][x] = 1;
  ++ans;
  for(int i=0;i<4;++i){
    int mx = x+dx[i];
    int my = y+dy[i];
    if(mx>=w || my>=h || mx<0 || my<0) continue;
    if(visited[my][mx] || tbl[my][mx]=='#') continue;
    dfs(mx,my);
  }
}

int main(){
  while(cin>>w>>h,w||h){
    memset(visited,0,sizeof(visited));
    ans = 0;
    for(int i=0;i<h;++i) cin >> tbl[i];
    int sx=-1,sy=-1;
    for(int i=0;i<h;++i)
      for(int j=0;j<w;++j)
	if(tbl[i][j]=='@')
	  sy=i,sx=j;

    dfs(sx,sy);
    cout << ans << endl;
}
  return 0;
}