import java.util.Scanner;
public class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		 long N =sc.nextLong();
         
      long a =0;
		for(long i=1;i<=N;i++) {
			if(i%3!=0&&i%5!=0) {
              a +=i;
            }
        }
          System.out.println(a);
		}
	}

/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