import java.util.Scanner;

public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = 0;

		n = sc.nextInt();
		long ans = 0;
        for (int i = 0; i < n+1; i++) {
            if(!(i % 3 == 0 || i % 5 == 0)){
            	ans += i;
            }
        }



			System.out.println(ans);

	}
}
/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