import java.util.*;
class Main
{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		long n = Long.parseLong(sc.next());
		
		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