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:
from queue import Queue

while True:
    w, h = map(int, input().split())
    if w == h == 0:
        break

    tile = [input() for i in range(h)]
    for x, col in enumerate(tile):
        if '@' in col:
            y = col.index('@')
            s = (x, y)
            break

    visit = [[False for i in range(w)] for j in range(h)]
    dx = (0, -1, 1, 0)
    dy = (1, 0, 0, -1)
    que = Queue()
    que.put(s)
    while not que.empty():
        x, y = que.get()
        if visit[x][y]:
            continue

        visit[x][y] = True
        for j in range(4):
            sx = x + dx[j]
            sy = y + dy[j]
            if sx < 0 or sx >= h or sy < 0 or sy >= w:
                continue
            if tile[sx][sy] != '#':
                que.put((sx, sy))

    ans = 0
    for col in visit:
        ans += col.count(True)

    print(ans)