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 codechef; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
public class Main
{
    public static boolean prime_factor(int n){
        int c=0;
        HashSet<Integer> set=new HashSet<Integer>();
        while(n%2==0)
        {
            n=n/2;
           set.add(2);
        }
        
        for(int i=3;i*i<=n;i+=2){
            while(n%i==0)
           {
                set.add(i);
                n=n/i;
               
           }
        }
        if(n>2)
        set.add(n);
        //System.out.println(set);
        if(set.size()==2) return true;
        return false;
        
    }
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt();
		int res=0;
		for(int i=2;i<=n;i++){
		   if(prime_factor(i)) res++;
		    }
		System.out.println(res);
		
	}
}
