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
import java.util.ArrayList;
import java.util.Scanner;
public class Problem26A {
    public static ArrayList<Integer> getFactors(int n) {
        ArrayList<Integer> factors = new ArrayList<Integer>();
        for (int i = 2; i <= n/2; i++) {
            if (n%i==0) {
                if(isPrime(i)) {
                    factors.add(i);
                }
            }
        }
        return factors;
    }
    public static boolean isPrime(int num) {
        int length = (int) Math.sqrt(num);
        for (int i = 2; i <= length; i++) {
            if (num%i==0)
                return false;
        }
        return true;
    }
    public static void main (String[] args) {
        Scanner sc = new Scanner (System.in);
        int n = sc.nextInt();
        ArrayList<Integer> factors = new ArrayList<Integer>();
        int count = 0;
        
        for (int i = 6; i <= n; i++) {
            if(getFactors(i).size()==2)
                count++;
        }
        System.out.println(count);
    }
}