I have to prepare an adjusting entry for Dec 31, 2008 for prepaid insurance from this: An analysis

I have to prepare an adjusting entry for Dec 31, 2008 for prepaid insurance from this: An analysis of the company’s insurance policies provided these facts: Policy A Purchased on April 1, 2007 for 24 month at $11400. Policy B Purchased on April 1, 2008 for 36 months at $10200. Policy C Purchased on August 1, 2008 for 12 months at $9000. The total premium for each policy was paid in full (for all months) at the purchase date, and the Prepaid Insurance account was debited for the full cost. (Year-end adjusting entries for Prepaid Insurance were properly recorded in all prior years.) I can’t seem to figure out how much money to debit insurance expense for and to credit prepaid insurance. Can anyone help? THANKS.