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:
#!/usr/bin/env python
# conding: utf

from logging import getLogger, StreamHandler, NullHandler, DEBUG, INFO
logger = getLogger(__name__)
#handler = StreamHandler()
handler = NullHandler()
logger.setLevel(DEBUG)
handler.setLevel(DEBUG)
logger.addHandler(handler)
logger.propagate = False

g_field = []
g_count = 0
g_W = -1
g_H = -1

OFFSETS = [(1,0), (-1,0), (0,1), (0,-1)]

def dfs(x, y):
    global g_field
    global g_count
    global g_W
    global g_H


    g_count += 1

    g_field[y][x] = "-"

    for dx, dy in OFFSETS:
        logger.debug("diff: {} {}".format(dx, dy))
        new_x = x + dx
        new_y = y + dy

        if new_x < 0 or new_x >= g_W:
            continue
        if new_y < 0 or new_y >= g_H:
            continue
        new_tile = g_field[new_y][new_x]
        if new_tile == "#" or new_tile == "-":
            continue

        logger.debug("{}, {}".format(new_x, new_y))
        dfs(new_x, new_y)


if __name__ == "__main__":
    while True:
        g_W, g_H = [int(s) for s in input().strip().split()]

        if g_W == 0 and g_H == 0:
            break
        
        g_field = []
        for _ in range(g_H):
            row = list(input().strip())
            g_field.append(row)
        g_count = 0

        for y in range(g_H):
            for x in range(g_W):
                if g_field[y][x] == "@":
                    start_x = x
                    start_y = y
                    break

        dfs(start_x, start_y)

        print(g_count)