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 PYTHON3):

Solution:
while True:
    W, H = map(int, input().split())
    if W == 0 and H == 0:
        break
    maze = []
    for _ in range(H):
        maze.append(list(input()))
    visited = [[False] * W for _ in range(H)]
    dxy = [(1, 0), (0, 1), (-1, 0), (0, -1)]
    ans = 0


    def rec(x, y):
        global ans
        visited[x][y] = True
        ans += 1
        for (dx, dy) in dxy:  # 4方向の移動を試す
            x2 = x + dx
            y2 = y + dy
            if 0 <= x2 < H and 0 <= y2 < W:
                if maze[x2][y2] == '.':
                    if not visited[x2][y2]:
                        rec(x2, y2)  # 再帰呼び出し


    for h in range(H):
        for w in range(W):
            if maze[h][w] == '@':
                rec(h, w)
                break
        else:
            continue
        break

    print(ans)