A number is called almost prime if it has exactly two distinct prime divisors. For example, numbers 6, 18, 24 are almost prime, while 4, 8, 9, 42 are not. Find the amount of almost prime numbers which are between 1 and n, inclusive.

Input

Input contains one integer number n (1 ≤ n ≤ 3000).

Output

Output the amount of almost prime numbers between 1 and n, inclusive.

Examples

Input

10


Output

2


Input

21


Output

8
//package round26;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Scanner;

public class A {
	private Scanner in;
	private PrintWriter out;
	private String INPUT = "";
	
	public void solve()
	{
		int n = ni();
		int[] a = new int[n + 1];
		int ct = 0;
		for(int p = 2;p <= n;p++){
			if(a[p] == 0){
				for(int i = p;i <= n;i += p){
					a[i]++;
				}
			}else if(a[p] == 2){
				ct++;
			}
		}
		out.println(ct);
	}
	
	public void run() throws Exception
	{
		in = INPUT.isEmpty() ? new Scanner(System.in) : new Scanner(INPUT);
		out = new PrintWriter(System.out);
		
		solve();
		out.flush();
	}
	
	
	public static void main(String[] args) throws Exception
	{
		new A().run();
	}
	
	private int ni() { return Integer.parseInt(in.next()); }
	private void tr(Object... o) { if(INPUT.length() == 0)System.out.println(o.length == 1 ? o[0] : Arrays.toString(o)); }
}
