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:
vec = [[1,0],[0,1],[-1,0],[0,-1]]

def dfs(nw,nh):
    global count
    count += 1
    visited[nh][nw] = True
    for x,y in vec:
        new_w = nw + x
        new_h = nh + y
        if (0 <= new_w) and (new_w) < w:
            if (0 <= new_h) and (new_h) < h:
                if (lis_f[new_h][new_w] == ".") and (visited[new_h][new_w] == False):
                    dfs(new_w,new_h)
                    
while(True):
    w,h = map(int,input().split())
    if (w,h) == (0,0):
        break
    lis_f = []
    for _ in range(h):
        lis_f.append(list(input()))
    
    visited = [[False for _ in range(w)] for _ in range(h)]
    count = 0
    
    id_w = 0
    id_h = 0
    set_w = 0
    set_h = 0
    while(id_h < h):
        while(id_w < w):
            #print(lis_f[id_h][id_w])
            if lis_f[id_h][id_w] == "@":
                set_w = id_w
                set_h = id_h
            id_w += 1
        id_h += 1
        id_w = 0
    
    #print(set_w,set_h)
    
    dfs(set_w,set_h)
    print(count)