when you arrive, you'll be stamped a 21 day visa.
before that expires you can extend that for 38 days... 21+38 = 59 days
you can then extend for either 1 month or 2 months.
then just keep on extending...
i don't know if they changed the rules again...but last Feb i extended my fiances visa...max was 2 months per extension.
correct me if am wrong.
thanks.