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:
        break
    a = []
    for i in range(h):
        t = list(input())
        a.append(t)
        if '@' in t:
            x = i
            y = t.index('@')
    stk = [[x, y]]
    c = 1
    while True:
        if stk == []:
            break
        x, y = stk.pop()
        if y != w-1 and a[x][y+1] == '.':
            a[x][y+1] = '@'
            stk.append([x, y+1])
        if y != 0 and a[x][y-1] == '.':
            a[x][y-1] = '@'
            stk.append([x, y-1])
        if x != h-1 and a[x+1][y] == '.':
            a[x+1][y] = '@'
            stk.append([x+1, y])
        if x != 0 and a[x-1][y] == '.':
            a[x-1][y] = '@'
            stk.append([x-1, y])
    print(sum([t.count('@') for t in a]))