import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		long n = scan.nextLong();

		long total = 0;

		for(int i = 1; i <= n; i++) {

			if(i % 3 != 0 && i % 5 != 0 ) {
				total += i;
			}
			
		}

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