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 w, h;
char d[20][25];
bool wasOn[20][20];
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};

int solve(int x, int y) {
  if (x < 0 || y < 0 || x >= w || y >= h) return 0;
  if (d[y][x] == '#') return 0;
  if (wasOn[y][x]) return 0;
  wasOn[y][x] = true;
  int ans = 1;
  for (int i = 0; i < 4; i++) ans += solve(x + dx[i], y + dy[i]);
  return ans;
}

int main() {
  while (1) {
    scanf("%d%d", &w, &h);
    if (w == 0) break;
    for (int i = 0; i < h; i++) scanf("%s", d[i]);
    int x, y;
    for (int i = 0; i < h; i++) {
      for (int j = 0; j < w; j++) {
        wasOn[i][j] = false;
        if (d[i][j] == '@') y = i, x = j;
      }
    }
    printf("%d\n", solve(x, y));
  }
}