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:
h=0
w=0

while 1:
    w,h=map(int,input().split())
    if h==0 and w==0:
        break
    grid=[]
    sx=-1
    sy=-1
    ans=1
    used=[[0]*w for i in range(h)]
    def valid(i,j):
        return i>=0 and j>=0 and i<h and j<w and grid[i][j]=='.' and not used[i][j]
    for i in range(h):
        row=input()
        grid.append(row)
        for j in range(w):
            if row[j]=='@':
                sx=i
                sy=j
    stk=[(sx,sy)]
    while stk:
        x=stk[-1][0]
        y=stk[-1][1]
        stk.pop()
        for d in [(1,0),(0,1),(-1,0),(0,-1)]:
            xx=x+d[0]
            yy=y+d[1]
            if valid(xx,yy):
                stk.append((xx,yy))
                used[xx][yy]=1
                ans+=1
    print(ans)