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 queue
dxy=[(1,0),(0,1),(-1,0),(0,-1)]
def bfs(sx,sy,H,W):#幅優先探索
    q=queue.Queue()
    visited=[[False]*W for _ in range(H)]
    q.put((sx,sy))
    visited[sx][sy]=True
    ans=1
    while not q.empty():
        px,py=q.get()
        for dx,dy in dxy:
            nx=px+dx
            ny=py+dy
            if 0<=nx<H and 0<=ny<W:
                if c[nx][ny]=='.' and visited[nx][ny]==False:
                    visited[nx][ny]=True
                    q.put((nx,ny))
                    ans+=1
    return ans
while True:
    W,H=map(int,input().split())
    if(W==0 and H==0):
        break
    c=[input() for _ in range(H)]
    for i in range(H):
        if "@" in c[i]:
            sx=i
            sy=c[i].index("@")
    print(bfs(sx,sy,H,W))