import java.util.*;
public class Main {
	public static void main(String[] args){
      	
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		long cnt =0;
		for (long i = 1; i < N+1; i++) {
			if (i%3==0||i%5==0) {
				
			}else{
				cnt += i;
			}
		}
		System.out.println(cnt);
		sc.close();
    }	
		
}
/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