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:
#coding: utf-8

def Is_black(coo):
    a = coo[0]
    b = coo[1]
    if 0 <= a < l[1] and 0 <= b < l[0] and \
    map_list[a][b] == '.':
        return True
    else:
        return False

while True:
    l = map(int, raw_input().split())
    if l == [0, 0]:
        break
    else:
        map_list = []
        for i in range(l[1]):
            row = str(raw_input())
            if '@' in row:
                fp = (i, row.find('@'))
            map_list.append(row)
        stack = [fp]
        arrived = [fp]
        while stack:
            coo = stack.pop()
            coo_a = (coo[0], coo[1] + 1)
            coo_b = (coo[0], coo[1] - 1)
            coo_c = (coo[0] + 1, coo[1])
            coo_d = (coo[0] - 1, coo[1])
            coo_l = [coo_a, coo_b, coo_c, coo_d]
            for c in coo_l:
                if Is_black(c) and c not in arrived:
                    stack.append(c)
                    arrived.append(c)
        print len(arrived)