import java.util.*;

public class Main{
    public static void main(String args[]){
        Scanner sn = new Scanner(System.in);
        long N = sn.nextInt();
        long result = 0;

        for(int i=1; i<=N; i++){
            if(i%3 == 0 | i%5 == 0){
                continue;
            }else{
                result += i;
            }
        }

        System.out.println(result);
    }
}
/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