import java.util.*;
import java.lang.*;

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

        Scanner s = new Scanner(System.in);

        int n =s.nextInt();
        long sum=0;

        for(int i=1;i<=n;i++){
            if(i%3!=0 && i%5!=0){
                sum=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