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:
from collections import defaultdict
def explore(now,cnt):
    if cnt>W*H:#理論的にはW*H以下で全部回れるので
        a=0 #無駄なコード
    else:
        d[now]=1
        if now[1]+1<W:
            if not data[now[0]][now[1]+1]=="#":
                if not (now[0],now[1]+1) in d.keys():
                    explore((now[0],now[1]+1),cnt+1)
        if now[0]+1<H:
            if not data[now[0]+1][now[1]]=="#":
                if not (now[0]+1,now[1]) in d.keys():
                    explore((now[0]+1,now[1]),cnt+1)
        if now[0]-1>=0:
            if not data[now[0]-1][now[1]]=="#":
                if not (now[0]-1,now[1]) in d.keys():
                    explore((now[0]-1,now[1]),cnt+1)
        if now[1]-1>=0:
            if not data[now[0]][now[1]-1]=="#":
                if not (now[0],now[1]-1) in d.keys():
                    explore((now[0],now[1]-1),cnt+1)
    
while True:
    W,H=map(int,input().split())
    if W==0 and H==0:
        break
    data=[list(input()) for _ in range(H)]
    d=defaultdict()
    for i in range(H):
        for j in range(W):
            if data[i][j]=="@":
                start=(i,j)
                break
    now=start
    cnt=0
    explore(now,cnt)
    print(len(d.keys()))