import java.io.*;

public class PrimoPar {

  public static boolean par(int num)
  {
    if (num % 2 == 0)
    {
      return true;
    }
    else
    {
      return false;
    }
  }

  public static boolean perfecto(int num) {

    int sum = 0;
    for(int i = 1; i < num; i++)
    {
      if(num % i == 0)
      {
        sum += i;
      }
    }

    if (sum == num)
    {
      return true;
    }
    else
    {
      return false;
    }
  }

  public static void main(String[] args) throws IOException {

    int a,b,cont = 0;

    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));

    System.out.print("a : ");
    a = Integer.parseInt(in.readLine());

    System.out.print("b : ");
    b = Integer.parseInt(in.readLine());

    for(int i = a; i <= b; i++)
    {
      if ( par(i) && perfecto(i) )
      {
        System.out.print(i + "\t");
        cont++;
      }
    }

    System.out.println("\n\nExisten " + cont + " numeros que cumplen la condicion");

  }
}