计算并返回贷款利息（假设起始贷款金额loan为L－－本金，银行年利率为R，则月利率为R/12，银行核算利息时采用月利息计算，所得的利息加入到本金中，作为下个月的本金，以此类推），一般年利率为6 。要求输入如下几个参数：初始贷款金额L、银行年利率rate、借期N年（月），计算后返回：应偿还的总金额T total（假设每月偿还等额的本金）。

l-(L*R/12+L)

-Loan interest calculation and returns (assuming the initial loan amount loan for the L- the principal, the bank interest rate of R, then the monthly rate R/12, bank accounts with monthly interest when the interest calculation, interest income added to principal in the As next month' s principal, and so on), the general rate was 6 . Asked to enter several parameters as follows: the initial loan amount L, bank interest rate rate, by period of N years (January), computed returns: the total amount repayable T total (assuming equal monthly repayment of principal.) l-(L* R/12+ L)