import java.util.*;
public class Main {

    public static void main(String[] args) {
        Scanner  yomi = new Scanner(System.in);
        long n = yomi.nextLong();
        long a = 0;
        for(long i = 1;i<=n;i++){
            if (i%3!=0 && i%5!=0){
                a = 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