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 deque
d = [(1,0),(-1,0),(0,1),(0,-1)]
while 1:
    w,h = map(int, input().split())
    if w == h == 0:
        break
    s = [input() for i in range(h)]
    bfs_map = [[1 for i in range(w)] for j in range(h)]
    for y in range(h):
        for x in range(w):
            if s[y][x] == "@":
                ans = 1
                q = deque()
                q.append((y,x))
                bfs_map[y][x] = 0
                while q:
                    y, x = q.popleft()
                    for dy,dx in d:
                        y_ = y+dy
                        x_ = x+dx
                        if 0 <= y_ < h and 0 <= x_ < w:
                            if bfs_map[y_][x_] and s[y_][x_] == ".":
                                ans += 1
                                bfs_map[y_][x_] = 0
                                q.append((y_,x_))
                print(ans)
                break