import java.util.Scanner;

public class Main {
    public static void main(String[] args){

        boolean enable=false;
        Scanner sc=new Scanner(System.in);
        long l=sc.nextLong();
        long sum=0;
        for(long i=1;i<=l;i++){
            if(i%3 ==0 || i%5==0){
                continue;
            }
            sum +=i;
        }
        System.out.println(sum);
    }

}
/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