知道复利终值求本金

package calculation2;

import java.util.Scanner;

public class calculation3 {

    public static void main(String[] args) {
        // TODO 自动生成的方法存根
         double N=1,money;
          Scanner scanner=new Scanner(System.in);
          System.out.print("请输入复利终值：");     
          double sum = scanner.nextDouble();  
          System.out.print("请输入存钱年数：");
          int years = scanner.nextInt();           
         System.out.print("请输入利率：");
          double r = scanner.nextDouble();
          for(int i=1;i<=years;i++){
               N=(1+r)*N;
           }
             money=sum/N;
             System.out.println("应投入的本金为："+money);
    }

}