import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) {
		try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
			long n = Long.parseLong(br.readLine());
			long cnt = 0;

			for (long i = 1; i < n + 1; i++) {
				if (i % 15 == 0) {
					cnt += 4; // FizzBuzz
				} else if (i % 3 == 0 || i % 5 == 0) {
					cnt += 2; // Fizz or Buzz
				} else {

				}
			}

			System.out.println(cnt);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

}