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 JAVA):

Solution:
import java.util.Scanner;

// ??±???????????¢?´¢
public class Main {
    static int w, h;
    static int[][] map;
    static int c;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (true) {
            w = sc.nextInt();
            h = sc.nextInt();
            if ((w | h) == 0) {
                break;
            }
            map = new int[h][w];
            int sx = 0;
            int sy = 0;
            c = 0;
            for (int i = 0; i < h; i++) {
                String line = sc.next();
                for (int j = 0; j < w; j++) {
                    if (line.charAt(j) == '@') {
                        sy = i;
                        sx = j;
                        map[i][j] = 0;
                    } else {
                        map[i][j] = line.charAt(j) == '.' ? 0 : 1;
                    }
                }
            }
            dfs(sy, sx);
            System.out.println(c);
        }
    }

    public static void dfs(int y, int x) {
        if (y < 0 || y >= h || x < 0 || x >= w) {
            return;
        }
        if (map[y][x] == 1) {
            return;
        }
        map[y][x] = 1;
        int[] d = new int[] { 0, 1, 0, -1, 0 };
        for (int i = 0; i < 4; i++) {
            dfs(y + d[i], x + d[i + 1]);
        }
        c++;
    }

}