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 PYTHON):

Solution:
def search(here, lb, ub, field):
	count = 0
	if field[here[1]][here[0]] :
		count += 1
		field[here[1]][here[0]] = 0
		if lb[0] < here[0] :
			count += search((here[0]-1, here[1]), lb, ub, field) 
		if lb[1] < here[1] :
			count += search((here[0], here[1]-1), lb, ub, field)
		if ub[0] > here[0] :
			count += search((here[0]+1, here[1]), lb, ub, field)
		if ub[1] > here[1] :
			count += search((here[0], here[1]+1), lb, ub, field) 
	return count

while 1:
	w, h = map(int, raw_input().split(" "))
	if (w,h) == (0,0): 
		break
	field = [[1 for i in range(w)] for j in range(h)]
	for y in range(h):
		tiles = raw_input()
		for x in range(w):
			if tiles[x] == "#":
				field[y][x] = 0
			elif tiles[x] == "@":
				here = (x,y)
	print search(here, (0,0), (w-1,h-1), field)