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
while True:
    w,h = map(int,input().split())
    if w==0 and h==0:
        break
    tile=[]
    tile.append(["#"]*(w+2))
    for _ in range(h):
        temp= list(input())
        temp=  ["#"]+ temp + ["#"]
        tile.append(temp)
    tile.append(["#"]*(w+2))

    route=[[[0,0,0,0] for i in range(w)] for j in range(h)]
    for i in range(1,h+1):
        for j in range(1,w+1):
            if tile[i+1][j] ==".":
                route[i-1][j-1][0]= 1
            if tile[i-1][j] ==".":
                route[i-1][j-1][1]= 1
            if tile[i][j+1] ==".":
                route[i-1][j-1][2]= 1
            if tile[i][j-1] ==".":
                route[i-1][j-1][3]= 1
            if tile[i][j]=="@":
                st=[i-1,j-1]

    dir= [[1,0],[-1,0],[0,1],[0,-1]]
    d=[[0]*w for i in range(h)]
    d[st[0]][st[1]]=1
    q= collections.deque()
    q.append(st)
    while len(q)> 0:
        cur = q.popleft()
        for i in range(4):
            if route[cur[0]][cur[1]][i]==1 and d[cur[0]+dir[i][0]][cur[1]+dir[i][1]]==0:
                d[cur[0]+dir[i][0]][cur[1]+dir[i][1]]=1
                q.append([cur[0]+dir[i][0],cur[1]+dir[i][1]])

    ans=0
    for i in range(h):
        for j in range(w):
            if d[i][j] == 1:
                ans+=1
    print(ans)