import java.util.Scanner;

public class Main{
  public static void main(String args[]){
    Scanner scan = new Scanner(System.in);
    long N = scan.nextInt();
    long total = 0;
    
    for(int i = 0; N != i; N--){
      if(N%3 != 0&&N%5 != 0){
        total += N;
      }
    }
    System.out.print(total);
    }
  }





/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz