package yukicoder;

import java.util.Scanner;

public class Yuki311 {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		long num = scan.nextLong();
		scan.close();
	    System.out.println((num / 5 + num / 3) * 2);
		/*
		long ans = 0;
		String strArr = "";
		for (long i = 1; i <= num; i++) {

			if (i % 3 == 0 && i % 5 == 0) {
				strArr = "FizzBuzz";
			} else if (i % 3 == 0) {
				strArr = "Fizz";
			} else if (i % 5 == 0) {
				strArr = "Buzz";
			} else {
				strArr = "";
			}	
		
			for (long j = 0; j < strArr.length(); j++) {
				if ('z' == strArr.charAt((int)(j))) {
					ans++;
				}
			}
		}
		System.out.println(ans);
		*/
	}
}