public class PostageMeter {
  
  public static String threeFive(int n) {
    
    // bases cases
    if (n == 8) {
      return "5+3";
    }
    if (n == 9) {
      return "3+3+3";
    }
    if (n == 10) {
      return "5+5";
    }
    // inductive step
    if (n > 10) {
      return threeFive(n-3) + "+3";
    }
    
    // lazy default
    return "I don't know how to make postage for " + n;
  }
}