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.

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.

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).

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

45 59 6 13

Source: ACM International Collegiate Programming Contest
, Japan Domestic Contest, Ehime, Japan, 2004

http://www.ehime-u.ac.jp/ICPC/

http://www.ehime-u.ac.jp/ICPC/