Algodoo

I would appreciate it if someone could make a leg for me, it would be very helpful...
This has a really weird name for a title LOL
Anyways, this is how it works:
In this type of marble race, it starts off with only one leg.
Then, I make another leg and combine both legs.
Then, I make a third leg and combine all of the legs together.
The process continues until we have a winner.