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 dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};
int a,b,sum=0;
int y[21][21]={};
char x[21][21];
void dfs(int aa,int bb){
for(int i=0;i<4;i++){
  if(aa+dx[i]>=0 && aa+dx[i]<a && bb+dy[i]>=0 && bb+dy[i]<b && y[bb+dy[i]][aa+dx[i]]==0){
y[bb+dy[i]][aa+dx[i]]=1;
dfs(aa+dx[i],bb+dy[i]);
}
}
}
int main(){
int c,d;
while(1){
scanf("%d %d",&a,&b);
if(a==0 && b==0) break;
for(int i=0;i<b;i++){
scanf("%s",x[i]);
}
for(int i=0;i<b;i++){
for(int j=0;j<a;j++){
if(x[i][j]=='.'){
y[i][j]=0;
}else if(x[i][j]=='#'){
y[i][j]=2;
}else{
	y[i][j]=1;
c=j;
d=i;
}
}}
dfs(c,d);
for(int i=0;i<b;i++){
  for(int j=0;j<a;j++){
    if(y[i][j]==1){
      sum++;
    }
  }
}
printf("%d\n",sum);
sum=0;
}
return 0;
}