import java.util.Scanner;
public class Main {
    public static void main(String[] args) throws Exception {
        Scanner stdIn= new Scanner(System.in);
        int x = stdIn.nextInt();
        long a=0;
        for(int i=1;i<=x;i++){
            if(i%3==0||i%5==0)continue;
            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