import java.util.Scanner;

class FizzBuzzString {
  public static void main(String[] args) {
    Scanner stdIn = new Scanner(System.in);

    long n= stdIn.nextLong();
    long z = 0;

    for ( long i = 0; i < n; i++ ) {
      if ( i % 3 == 0 && i % 5 == 0 ) {
        z += 4;
      } else {
        if ( i % 3 == 0 ) {
          z += 2;
        }
        if ( i % 5 == 0 ) {
          z += 2;
        }
      }
    }
    System.out.println(z);
  }
}