One of your customers is delinquent on his accounts payable balance. You’ve mutually agreed to a repayment schedule of $949 per month. You will charge 3.5 percent per month interest on the overdue balance. If the current balance is $19960, how many months will it take for the account to be paid off? (Round your answer to 2 decimal places. For example, 12.3456 should be entered as 12.35.)