Recurrence relation for amount in account at end of n years if no money withdrawn.

A deposit of 50000 O.R.is maid to an investment fund at the beginning of a year.On the last day of each year two dividends are awarded.The first dividend is 20% of the amount in the account during that year. The second dividend is 45% of the amount in the account in the previous year.

(a)Find a recurrence relation for {pn}, where pn is the amount in the account at the end of n years if no money is ever withdrawn.

hope someone can help me, and thanks in advance.