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 python3
# -*- coding: utf-8 -*-

import array
import itertools
import sys


UNDET_POINT = (-1, -1)


class RecursiveDepthFirstSearch(object):

    def __init__(self, width, height, tiles):
        self.width = width
        self.height = height
        self.tiles = tiles
        self.reached = [array.array(
            "B", (False for j in range(height))) for i in range(width)]
        self.start_tile = UNDET_POINT
        for x, y in itertools.product(range(width), range(height)):
            if tiles[x][y] == "@":
                self.start_tile = (x, y)
                break

    def search(self, x, y):
        if x < 0 or self.width <= x or y < 0 or self.height <= y:
            pass
        elif self.tiles[x][y] == "#":
            pass
        elif self.reached[x][y]:
            pass
        else:
            self.reached[x][y] = True
            self.search(x + 1, y)
            self.search(x - 1, y)
            self.search(x, y + 1)
            self.search(x, y - 1)

    def count_reachable_tiles(self):
        self.search(*self.start_tile)
        reachable_tiles = sum([self.reached[x][y] for x, y in itertools.product(
            range(self.width), range(self.height))])
        return reachable_tiles


if __name__ == "__main__":
    sys.setrecursionlimit(10000)
    while True:
        width, height = map(int, input().split())
        if width == 0 and height == 0:
            break
        else:
            tiles = [x for x in zip(*[input() for y in range(height)])]
            dfs = RecursiveDepthFirstSearch(width, height, tiles)
            print(dfs.count_reachable_tiles())