using System;

public class problem23{
  public static void Main(){
      int size = 28123;
      int[] array = new int[size];

      for(int i = 0; i<size-1; i++){
        array[i] = 1;
      }
/*
      int sum = 0;
      for(int i = 0; i<size; i++){
        if(isAbundant(i)){
          Console.WriteLine(i);
          sum++;

        }
      }
      Console.WriteLine(sum);
*/
      for(int i= size-1 ; i>0 ; i--) {
        for(int j = 12 ; j<i ; j++ ){
          int temp = i - j;
          if(isAbundant(j) && isAbundant(temp)){
            array[i] = 0;
            Console.WriteLine(j +"\t"+ temp+"\t"+ i);
            break;
          }
        }
      }
      int total = 0;
      for(int i= size-1 ; i>0 ; i--){
        if(array[i] == 1){
          total += i;
        }
      }
      Console.WriteLine(total);
  }

  private static bool isAbundant(int n){
    return allFactors(n) > n;
  }

  private static int allFactors(int n){
    int total = 0;
    double limit = Math.Sqrt(n);
    for(int i=1;i<limit;i++){
      if(n%i==0){
        total += (i+n/i);
      }
    }
    return total-n;
  }



}