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 math

def search(w,h,data): 
    for i in range(h):
        if '@' in data[i]:
            stx,sty = i,data[i].index('@')

    stack = [[stx,sty]]
    check = [[stx,sty]]
    while True:
        if len(stack) != 0:
            s = stack[-1]
            Hnow,Wnow = s[0],s[1]
        else:
            return len(check)

        stack.pop()
        
        if Hnow < h-1:
            if (data[Hnow+1][Wnow] == '.') and ([Hnow+1,Wnow] not in check):
                stack.append([Hnow+1,Wnow])
                check.append([Hnow+1,Wnow])

        if Wnow < w-1:
            if (data[Hnow][Wnow+1] == '.') and ([Hnow,Wnow+1] not in check):
                stack.append([Hnow,Wnow+1])
                check.append([Hnow,Wnow+1])

        if Hnow > 0:
            if (data[Hnow-1][Wnow] == '.') and ([Hnow-1,Wnow] not in check):
                stack.append([Hnow-1,Wnow])
                check.append([Hnow-1,Wnow])

        if Wnow > 0:
            if (data[Hnow][Wnow-1] == '.') and ([Hnow,Wnow-1] not in check):
                stack.append([Hnow,Wnow-1])
                check.append([Hnow,Wnow-1])

a = []


while True:
    w,h = list(map(int,input().split()))
    if (w == 0)and(h == 0):
        break
    else:
        data = [list(input()) for l in range(h)]
        a.append(search(w,h,data))

for i in a:
    print(i)