作業四----

size 200 200
paper 90
command square x y s c
{
pen c (10-C) (80*C)

line x y (x+s) (y+s)
line x (y+s) (x+s) y
line (x+s) (y+s) (x+s) y
line (x+s) y x y
}
repeat A 0 20
{
repeat B 0 20
{
square (A*10+2) (B*10+2) 10 (100-(A*B-50))
}


}