Lessor shall have the right to require Lessee to pay any past due sum (including the penalty and interest) in cash or bank cashier’s check as Lessor thinks appropriate. If Lessee fails to pay Rent and/or Service Fee when due 2 (two) or more time during any 6 (six) calendar months, Lessor shall have right to require Lessee to pay Rent and Service Fee in quarterly installments in advance instead of monthly payment for the balance of the Term or for any period as Lessor thinks appropriate.