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 collections

dx = [-1,0,1,0]
dy = [0,-1,0,1]
def movable(dst):
    if dst[0]<0 or dst[0]>b-1:
        return False
    elif dst[1]<0 or dst[1]>a-1:
        return False
    elif MM[dst[0]][dst[1]] == '#':
        return False
    else:
        return True

while True:
    c = 1
    a,b = map(int,input().split())
    if a==0 and b==0:
        exit()
    else:
        MM = []
        for i in range(b):
            q = list(input())
            MM.append(q)
            if '@' in q:
                st = [i, q.index('@')]

        D = [[-1 for _ in range(a)] for _ in range(b)]
        D[st[0]][st[1]] = 0 # 始点への距離は 0, 他の距離は-1
        Q = collections.deque()
        Q.append(st) # 始点
        while len(Q) > 0:
            #print("bfs", Q) # 各ステップでの Q の動作を確認
            cur = Q.popleft()
            for dir in range(4):
                # curからdstに移動可能かつ、dstが未訪問だったら
                dst = [cur[0]+dx[dir], cur[1]+dy[dir]]
                #print(dst)
                if movable(dst) and D[dst[0]][dst[1]] == -1:
                    D[dst[0]][dst[1]] = D[cur[0]][cur[1]]+1
                    c += 1
                    Q.append(dst) # Qにdstを詰める
        print(c)