import java.util.Scanner;

public class DoubleMoney
{
  public static void main (String args[])
  {
    Scanner kb = new Scanner(System.in);
    double principle;
    double rate;
    int month;

    System.out.println("Enter yearly interest rate:");
    rate = kb.nextDouble();
    rate = rate / 1200.0;

    month = 0;
    principle = 1.0;

    while(principle < 2.0)
    {
      month = month + 1;
      principle = principle * (1.0 + rate);
      System.out.println("After " + month + " months the principle is " + principle);
    }
  }
}