import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner scn = new Scanner(System.in);
		long N = scn.nextInt();
		scn.close();
		long sum = 0;
		for(long i = N;i>0;i--) {
			if(i%3 == 0) {
			}else if(i%5 == 0){
			}else {
			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