#include<iostream>
#include<string>
using namespace std;

char map[20][20];
int W,H;
int cnt;

void fac(int y,int x){
  map[y][x]='#';
  cnt++;
  
  if(map[y+1][x]=='.' && y < H-1)
    fac(y+1,x);
  if(map[y-1][x]=='.' && y > 0)
    fac(y-1,x);
  if(map[y][x+1]=='.' && x < W-1)
    fac(y,x+1);
  if(map[y][x-1]=='.' && x > 0)
    fac(y,x-1);  
}

int main(){
  int i,j;
  int x,y;

  while(1){
    cin >> W >> H;

    if(W+H==0)
      break;
    
    for(i=0;i<H;i++){
      for(j=0;j<W;j++){
	cin >> map[i][j];
	if(map[i][j]=='@'){
	  x=j; y=i; 
	} //@position      
      }
    }
    
    cnt=0;
    fac(y,x); //release cnt
    cout << cnt << endl;
  }
  return 0;
}
### Prompt

Your task is to create a Cpp solution to the following 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

### Response

```cpp
#include<iostream>
#include<string>
using namespace std;

char map[20][20];
int W,H;
int cnt;

void fac(int y,int x){
  map[y][x]='#';
  cnt++;
  
  if(map[y+1][x]=='.' && y < H-1)
    fac(y+1,x);
  if(map[y-1][x]=='.' && y > 0)
    fac(y-1,x);
  if(map[y][x+1]=='.' && x < W-1)
    fac(y,x+1);
  if(map[y][x-1]=='.' && x > 0)
    fac(y,x-1);  
}

int main(){
  int i,j;
  int x,y;

  while(1){
    cin >> W >> H;

    if(W+H==0)
      break;
    
    for(i=0;i<H;i++){
      for(j=0;j<W;j++){
	cin >> map[i][j];
	if(map[i][j]=='@'){
	  x=j; y=i; 
	} //@position      
      }
    }
    
    cnt=0;
    fac(y,x); //release cnt
    cout << cnt << endl;
  }
  return 0;
}
```