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:
def floodfill(matrix, x, y):
    global count
    #"hidden" stop clause - not reinvoking for "check" or "#", only for "," or "@".
    if (matrix[x][y] == ".") or (matrix[x][y] == "@"):
        count += 1
        matrix[x][y] = "check"
        #recursively invoke flood fill on all surrounding cells:
        if x > 0:
            floodfill(matrix, x - 1, y)
        if x < len(matrix) - 1:
            floodfill(matrix, x + 1, y)
        if y > 0:
            floodfill(matrix, x, y - 1)
        if y < len(matrix[0]) - 1:
            floodfill(matrix, x, y + 1)
    return count

while True:
    x, y = map(int, input().split())
    if x == y == 0: break
    room = []
    for i in range(y):
        room.append([i for i in input()])

    for key, list in enumerate(room):
        if "@" in list:
            ax, ay = key, list.index("@")

    count = 0
    print(floodfill(room, ax, ay))