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 dfs(x, y, W, H):
    if x >= H or y >= W or x < 0 or y < 0:
        return
    if visited[x][y] == 1:
        return
    if gridgraph[x][y] == '.' or gridgraph[x][y] == '@':
        visited[x][y] = 1
        dfs(x+1, y, W, H)
        dfs(x, y+1, W, H)
        dfs(x-1, y, W, H)
        dfs(x, y-1, W, H)
    if gridgraph[x][y] == '#':
        return

    return


while True:
    W, H = map(int, input().split())
    if W == 0 and W == 0:
        break
    gridgraph = [list(input()) for _ in range(H)]

    visited = [[0]*W for _ in range(H)]

    sx = -1
    sy = -1
    for i, row in enumerate(gridgraph):
        for j in range(len(row)):
            if row[j] == '@':
                sx = i
                sy = j
    dfs(sx, sy, W, H)

    ans = 0
    for row in visited:
        ans += sum(row)
    print(ans)