import java.util.*;

public class Main{
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		long n = scan.nextLong();
		long sum =0;

		for(long i=1; i<=n; i++){
			if(i % 3 == 0  || i %5 ==0 ){

			}else{
				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