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 PYTHON):

Solution:
def dfs(x, y):
    for dx in [-1, 0, 1]:
        for dy in [-1, 0, 1]:
            if abs(dx) + abs(dy) == 2 or abs(dx) + abs(dy) == 2:
                continue
            next_x, next_y = x + dx, y + dy
            if 0 <= next_x < H and 0 <= next_y < W and isVisited[next_x][next_y] == 0 and tile[next_x][next_y] == '.':
                isVisited[next_x][next_y] = 1
                dfs(next_x, next_y)
                
                

while True:
    W, H = map(int, raw_input().split())
    if W == 0 and H == 0: break
    tile = [raw_input() for _ in range(H)]
    ans = 0
    isVisited = [[0]*W for _ in range(H)]
    for cnt, t in enumerate(tile):
        if '@' in t:
            sx = cnt
            sy = t.index('@')
            break
    isVisited[sx][sy] = 1
    dfs(sx, sy)
    print sum([sum(v) for v in isVisited])