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).