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:
def dfs(graph, sx, sy):
    stack = [[sx, sy]]
    visited = []
    cnt = 0
    while stack:
        label = stack.pop(0)
        try:
            g = graph[label[1]][label[0]]
            if (label[0] < 0) or (label[0] > graph[0].__len__() - 1):
                continue
            if (label[1] < 0) or (label[1] >graph.__len__() - 1):
                continue
            if g == '#':
                continue
            if [label[0], label[1]] not in visited:
                # graph[label[1], label[0]] = '#'
                cnt += 1
                visited = [[label[0], label[1]]] + visited
                stack = [[label[0]+1, label[1]], [label[0]-1, label[1]], [label[0], label[1]+1], [label[0], label[1]-1]] + stack
        except IndexError:
            pass
    return cnt


if __name__ == '__main__':
    STR = []
    W, H = [int(i) for i in input().split()]
    while W != 0:
        for j in range(H):
            STR.append(list(input()))
            if '@' in STR[j]:
                sx, sy = STR[j].index('@'), j
        print(dfs(STR, sx, sy))
        STR = []
        W, H = [int(i) for i in input().split()]