Mark Mayer, a cash basis taxpayer, leased property on June 1, 2011 to Perry Purly at $325 a month. Perry paid Mark $325 as a security deposit, which will be returned at the end of the lease. In addition, Perry paid $650 in advance rent, which is to be applied as rent to the last two months in the lease term. The lease is to run for a two-year period. What is Mark's rental income for 2011?