import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 文字列の入力
		long n = sc.nextLong();

		long f = 0;
		for ( long i=1; i<=n; i++ ) {
			if ( i%3==0 || i%5==0 ) {
				continue;
			} else {
				f = f + i;
			}
		}
		System.out.println(f);
	}
}

/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