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 sys
from collections import deque

def solve():
    while 1:
        w, h = map(int, sys.stdin.readline().split())

        if w == h == 0:
            return

        room = [[False]*w for i in range(h)]

        si = sj = -1

        for i in range(h):
            line = input()

            for j, ch in enumerate(line):
                if ch == '@':
                    room[i][j] = True
                    si = i
                    sj = j
                elif ch == '.':
                    room[i][j] = True

        ans = bfs(w, h, room, si, sj)

        print(ans)

dx = (1, 0, -1, 0,)
dy = (0, 1, 0, -1,)

def bfs(w, h, room, si, sj):
    visited = [[False]*w for i in range(h)]
    visited[si][sj] = True
    q = deque([(si, sj)])
    cnt = 1

    while q:
        ci, cj = q.popleft()

        for k in range(len(dx)):
            ni = ci + dy[k]
            nj = cj + dx[k]

            if 0 <= ni < h and 0 <= nj < w and room[ni][nj] and not visited[ni][nj]:
                visited[ni][nj] = True
                q.append((ni, nj))
                cnt += 1

    return cnt

if __name__ == '__main__':
    solve()