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
/* -- Ved -- */

import static java.lang.System.out;
import java.util.*;

public class Almost_Prime{
    static boolean[] prime = new boolean[10000];
    static public void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int ans = 0;
        Arrays.fill(prime,true);
        prime[0] = false;
        prime[1] = false;
        for(int i = 2;i*i<10000;i++){
            if(prime[i]){
                for(int j = 2;j*i<10000;j++){
                    prime[j*i] = false;
                }
            }
        }
        for(int i = 2;i<=n;i++){
            if(is_Almost_Prime(i)){
                ans++;
            }
        }
        out.println(ans);
    }

    static boolean is_Almost_Prime(int n){
        int count =0;
        for(int i = 2;i<10000;i++){
            if(prime[i]==true){
                if(n%i == 0){
                    count++;
                }
            }
        }
        if(count==2){
            return true;
        }else{
            return false;
        }
    }
}