#include <iostream>
using namespace std;
#define BLACK '.'
#define RED '#'
#define PEOPLE '@'
#define N 25

char room[N][N];
int h,w;

int dx[4] = {1,0,-1,0};
int dy[4] = {0,1,0,-1};
int count(int x, int y){
  if( x<1 || x>w || y<1 || y>h )
    return 0;

  if( room[y][x] == RED )
    return 0;
  room[y][x] = RED;

  int r=1;
  for( int i=0;i<4;i++ )
    r += count(x+dx[i], y+dy[i]);
  return r;
}


int main(){
  int st_x, st_y;
  while( cin >> w >> h,(w|h) ){
    for( int i=1;i<=h;i++ ){
      for( int j=1;j<=w;j++ ){
	cin >> room[i][j];
	if( room[i][j] == PEOPLE ){
	  st_x=j;st_y=i;
	  room[i][j] = BLACK;
	}
      }
    }
    cout << count(st_x, st_y) << endl;
  }
}
### Prompt

Please formulate 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>
using namespace std;
#define BLACK '.'
#define RED '#'
#define PEOPLE '@'
#define N 25

char room[N][N];
int h,w;

int dx[4] = {1,0,-1,0};
int dy[4] = {0,1,0,-1};
int count(int x, int y){
  if( x<1 || x>w || y<1 || y>h )
    return 0;

  if( room[y][x] == RED )
    return 0;
  room[y][x] = RED;

  int r=1;
  for( int i=0;i<4;i++ )
    r += count(x+dx[i], y+dy[i]);
  return r;
}


int main(){
  int st_x, st_y;
  while( cin >> w >> h,(w|h) ){
    for( int i=1;i<=h;i++ ){
      for( int j=1;j<=w;j++ ){
	cin >> room[i][j];
	if( room[i][j] == PEOPLE ){
	  st_x=j;st_y=i;
	  room[i][j] = BLACK;
	}
      }
    }
    cout << count(st_x, st_y) << endl;
  }
}
```