#include <cstdio>

int W, H;
char tile[21][21];

int search(int y, int x) {
  if (tile[y][x] == '#') return 0;
  int cnt = 1;
  tile[y][x] = '#';
  if (y > 0)   cnt += search(y-1, x);
  if (y < H-1) cnt += search(y+1, x);
  if (x > 0)   cnt += search(y, x-1);
  if (x < W-1) cnt += search(y, x+1);
  return cnt;
}

int main() {
  while (true) {
    scanf("%d %d", &W, &H);
    if (W == 0 && H == 0) break;
    for (int i=0;i<H;i++) scanf("%s", tile[i]);
    int cnt = 0;
    for (int i=0;i<H;i++) {
      for (int j=0;j<W;j++) {
        if (tile[i][j] == '@') {
          cnt = search(i, j);
          break;
        }
      }
    }
    printf("%d\n", cnt);
  }
  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 <cstdio>

int W, H;
char tile[21][21];

int search(int y, int x) {
  if (tile[y][x] == '#') return 0;
  int cnt = 1;
  tile[y][x] = '#';
  if (y > 0)   cnt += search(y-1, x);
  if (y < H-1) cnt += search(y+1, x);
  if (x > 0)   cnt += search(y, x-1);
  if (x < W-1) cnt += search(y, x+1);
  return cnt;
}

int main() {
  while (true) {
    scanf("%d %d", &W, &H);
    if (W == 0 && H == 0) break;
    for (int i=0;i<H;i++) scanf("%s", tile[i]);
    int cnt = 0;
    for (int i=0;i<H;i++) {
      for (int j=0;j<W;j++) {
        if (tile[i][j] == '@') {
          cnt = search(i, j);
          break;
        }
      }
    }
    printf("%d\n", cnt);
  }
  return 0;
}
```