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

sys.setrecursionlimit(10**6)

W = None
H = None
MMAP = None
D = [(0,1),(0,-1),(1,0),(-1,0)]

def main():
    global W,H,MMAP,D
    while True:
        W,H = map(int,input().split())
        if not W and not H:
            return
        MMAP = [[] for _ in range(H)] # tiles[y][x]
        sx,sy = 0,0
        for y in range(H):
            row = list(input())
            if "@" in row:
                sy = y
                sx = row.index("@")
            MMAP[y] = row
        # gprint(tiles)
        print(calc(sx,sy))

def calc(x,y):
    global W,H,MMAP,D

    if not (x >= 0 and x < W and y >= 0 and y < H):
        return 0
    
    if MMAP[y][x] == "v" or MMAP[y][x] == "#":
        return 0

    # gprint(MMAP)
    # input()

    ssum = 1
    MMAP[y][x] = "v"

    for dx,dy in D:
        nx = x+dx
        ny = y+dy
        ssum += calc(x+dx,y+dy)

    return ssum

def gprint(tiles):
    for r in tiles:
        print(str("|".join(r)))


if __name__ == '__main__':
    main()