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).

## Sample Input

6 9
....#.
.....#
......
......
......
......
......
#@...#
.#..#.
11 9
.#.........
.#.#######.
.#.#.....#.
.#.#.###.#.
.#.#..@#.#.
.#.#####.#.
.#.......#.
.#########.
...........
11 6
..#..#..#..
..#..#..#..
..#..#..###
..#..#..#@.
..#..#..#..
..#..#..#..
7 7
..#.#..
..#.#..
###.###
...@...
###.###
..#.#..
..#.#..
0 0

## Output for the Sample Input

45
59
6
13