知道複利終值求本金

package calculation2;

import java.util.Scanner;

public class calculation3 {

    public static void main(String[] args) {
        // TODO 自動生成的方法存根
         double N=1,money;
          Scanner scanner=new Scanner(System.in);
          System.out.print("請輸入複利終值：");     
          double sum = scanner.nextDouble();  
          System.out.print("請輸入存錢年數：");
          int years = scanner.nextInt();           
         System.out.print("請輸入利率：");
          double r = scanner.nextDouble();
          for(int i=1;i<=years;i++){
               N=(1+r)*N;
           }
             money=sum/N;
             System.out.println("應投入的本金為："+money);
    }

}