
import java.util.Scanner;

public class Main {

  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    int n = scanner.nextInt();
    long sum =0;

    for (int i = 1; i <= n; i++) {
      if(i%5 != 0  && i%3 != 0) {
        sum += i;
      }
    }
    System.out.println(sum);
  }
}
