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:
from collections import deque

move = ((0,1),(1,0),(0,-1),(-1,0))

def inmap(x,y):
    if 0 <= x <= Lx-1 and 0<= y <= Ly-1:
        return True
    return False

while True:
    Lx,Ly = map(int,input().split())
    if Lx == 0:
        break
    curx= -1
    cury = -1
    orimap = [[] for _ in range(Ly)]
    for i in range(Ly):
        for j in input():
            orimap[i].append(j)
    for y in range(len(orimap)):
        for x in range(len(orimap[y])):
            if orimap[y][x] == "@":
                curx,cury = x,y
                orimap[y][x]="#"
                break
        if curx != -1:
            break
    Q = deque()
    Q.append([curx,cury])
    count = 1
    while len(Q)>0:
        curx,cury = Q.popleft()
        for dx,dy in move:
            nextx = curx + dx
            nexty = cury + dy
            if inmap(nextx,nexty):
                if orimap[nexty][nextx] != "#":
                    orimap[nexty][nextx] = "#"
                    Q.append([nextx,nexty])
                    count += 1
    print(count)