// IsPerfect.java

import java.util.*;

class IsPerfect {
  public static void main(String[] args) {
    int max;
    int n;
    
    Scanner scanner = new Scanner(System.in);
    System.out.print("Enter max number: ");
    max = scanner.nextInt();

    System.out.println("Here are the perfect #'s up to " + max + ":");    
    for (n=0; n<=max; n++) {
      if (isPerfect(n)) {
        System.out.println(n);
      }
    }
  }
  
  public static boolean isPerfect(int n) {
    int sumOfDivisors;
    int divisor;

    if (n < 1) {
      return false;
    }
            
    sumOfDivisors = 0;
    for (divisor=1; divisor<n; divisor++) {
      if (n % divisor == 0) {
        sumOfDivisors = sumOfDivisors + divisor;
      }
    }

    if (sumOfDivisors == n) {
      return true;
    }
    else {
      return false;
    }
  }
}