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 codeforces;

import java.util.*;

/**
 * Created by nitin.s on 01/04/16.
 */
public class AlmostPrime {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        boolean[] primes = new boolean[4000];
        Arrays.fill(primes, true);
        primes[0] = primes[1] = false;
        for(int i = 2; i * i < 4000; ++i) {
            if(primes[i]) {
                for(int j = i + i; j < 4000; j += i) {
                    primes[j] = false;
                }
            }
        }
        Set<Integer> primeDivisor = new HashSet<Integer>();
        int answer = 0;
        for(int num1 = 1; num1 <= n; ++num1) {
            primeDivisor.clear();
            for(int i = 0; i < 4000; ++i) {
                if(primes[i]) {
                    int num = num1;
                    if(num % i == 0) {
                        while(num != 0) {
                            primeDivisor.add(i);
                            num = num / i;
                        }
                    }
                }
            }
            if(primeDivisor.size() == 2) {
                ++answer;
            }
        }
        System.out.println(answer);
    }
}
