import java.util.Scanner;

public class yukicoder_311 {
	public static void main(String[] args) {
		Scanner stdIn = new Scanner(System.in);
		
		long n = stdIn.nextLong();
		
		long kosu = 0;
		
		for (long i = 1; i <= n; i++) {
			if ((i % 3 == 0) && (i % 5 == 0)) {
				kosu += 4;
			} else if ((i % 3 == 0) || (i % 5 == 0)) {
				kosu += 2;
			} else {
			}
		}
		System.out.print(kosu);
	}
}