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:
# coding: utf-8
def check(p):
    global ans
    global field
    ans+=1
    if(field[p[1]][p[0]]=='.'):
        field[p[1]][p[0]]='#'
    if(0<=p[0]+1<w and field[p[1]][p[0]+1]=='.'):
        check((p[0]+1,p[1]))
    if(0<=p[0]-1<w and field[p[1]][p[0]-1]=='.'):
        check((p[0]-1,p[1]))
    if(0<=p[1]+1<h and field[p[1]+1][p[0]]=='.'):
        check((p[0],p[1]+1))
    if(0<=p[1]-1<h and field[p[1]-1][p[0]]=='.'):
        check((p[0],p[1]-1))
    
    
while 1:
    ans=0
    w,h=map(int,input().split())
    if w==0:
        break
    field=[]
    for i in range(h):
        s=input()
        t=s.find('@')
        if(t!=-1):
            st=(t,i)
        field.append(list(s))
    check(st)
    print(ans)