import java.util.Scanner;
public class Main {

@SuppressWarnings("resource")
public static void main(String[] args) {
	Scanner sc =new Scanner(System.in);
	int N=sc.nextInt();
	long sum=0;
	for(int i=1;i<=N;i++) {
		if(i%3!=0&&i%5!=0) {
			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