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 = [int(n) for n in input().split()]

    if W == H == 0:
        break

    next_target = []

    room = []
    for n in range(H):
        s = list(input())
        room.append(s)
        for y in range(W):
            if s[y] == '@':
                next_target.append((n, y))

    result = 0

    while len(next_target) > 0:
        t = next_target.pop()

        # ???
        if t[0] - 1 >= 0 and room[t[0] - 1][t[1]] == '.':
            next_target.append((t[0] - 1, t[1]))
            room[t[0] - 1][t[1]] = '@'

        # ???
        if t[1] + 1 < W and room[t[0]][t[1] + 1] == '.':
            next_target.append((t[0], t[1] + 1))
            room[t[0]][t[1] + 1] = '@'

        # ???
        if t[0] + 1 < H and room[t[0] + 1][t[1]] == '.':
            next_target.append((t[0] + 1, t[1]))
            room[t[0] + 1][t[1]] = '@'

        # ???
        if t[1] - 1 >= 0 and room[t[0]][t[1] - 1] == '.':
            next_target.append((t[0], t[1] - 1))
            room[t[0]][t[1] - 1] = '@'

        # ?????????????????????????????????
        result += 1

    print(result)