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:
import sys

sys.setrecursionlimit(10000)


def dfs(x, y):
    global cout
    if 0 <= x < H - 1 and tile[x + 1][y] == ".":
        cout += 1
        tile[x + 1][y] = "#"
        dfs(x + 1, y)
    if 0 < x < H and tile[x - 1][y] == ".":
        cout += 1
        tile[x - 1][y] = "#"
        dfs(x - 1, y)
    if 0 <= y < W - 1 and tile[x][y + 1] == ".":
        cout += 1
        tile[x][y + 1] = "#"
        dfs(x, y + 1)
    if 0 < y < W and tile[x][y - 1] == ".":
        cout += 1
        tile[x][y - 1] = "#"
        dfs(x, y - 1)
    return 0


def search_start():
    for i in range(H):
        for j in range(W):
            if tile[i][j] == "@":
                tile[i][j] = "#"
                return (i, j)


if __name__ == "__main__":
    while True:
        W, H = map(int, input().split())
        if W == 0 and H == 0:
            break
        # print(W, H)
        tile = [list(input()) for _ in range(H)]
        cout = 1
        start = search_start()
        # print(start)
        dfs(start[0], start[1])
        # print(*tile, sep="\n")
        # print("total count : {}".format(cout))
        print(cout)