import java.util.Scanner;
public class Main{
 	public static void main(String[] args) {
 		Scanner stdIn=new Scanner(System.in);
 		int n=stdIn.nextInt();
 		long sum=0;
 		for(int i=1;i<n+1;i++) {
 			if(i%3!=0&&i%5!=0) {
 				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