import java.util.Scanner;
import java.io.PrintStream;

public class Test4G
{
   public static void main(String[] arguments)
   {
      PrintStream output = System.out;
      Scanner input = new Scanner(System.in);

      output.print("Enter a positive integer: ");
      final int N = input.nextInt();

      final int MULTIPLE = 3;
      for (int i = MULTIPLE; i < N; i = i + MULTIPLE)
      {
	  output.println(i);
      }
   }
}