import java.util.Scanner;
public class Main {
	public static void main(String[] args){

		Scanner sc = new Scanner(System.in);

		int A = sc.nextInt();

		long sum = 0;

		for(int i = 1; i <= A; i++){
			if(i % 3 == 0 || i % 5 == 0){
			} else {
				sum += i;
			}
		}

		System.out.print(sum);

	return;

	}
}

/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