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 == h == 0:
        break
    else:
        ans = 1
        L = []
        q = collections.deque()
        for i in range(h):
            s = input()
            T = []
            for j in range(w):
                if s[j] == '@':
                    T.append(0)
                    q.append([i,j])
                else:
                    T.append(s[j])
            L.append(T)
        dy_dx = [[1,0],[0,1],[-1,0],[0,-1]]
        while len(q) > 0:
            cur = q.popleft()
            for i in range(4):
                y = cur[0]+dy_dx[i][0]
                x = cur[1]+dy_dx[i][1]
                if 0 <= x < w and 0 <= y < h:
                    if L[y][x] == '.':
                        L[y][x] = L[cur[0]][cur[1]]+1
                        ans += 1
                        q.append([y,x])
        print(ans)