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

import static java.lang.Math.*;

public class AlmostPrimes {
    static StringTokenizer _stk; static BufferedReader input; static PrintWriter output; 
    static String next(){return _stk.nextToken();} static int nextInt(){return Integer.parseInt(next());}
    static String readln()throws IOException {String l=input.readLine();_stk=l==null?null:new StringTokenizer(l," ");return l;}
    public static void main(String[] args) throws IOException {
        input = new BufferedReader(new InputStreamReader(System.in)); 
        output = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
        new AlmostPrimes();
        output.close();
    }

    
    AlmostPrimes() throws IOException {
        readln();
        int n = nextInt();
        sieve(n);
        System.out.println(numAlmost);
    }
    
    private LinkedList<Integer> almost;
    int numAlmost;
    private int divisores[];
    private void sieve(int N) {
        divisores = new int[N+1];
        //divisores[1] = true;
        //int raiz = (int)sqrt(N);
        for(int i=2; i<=N/2; i++)
            if(divisores[i]==0)
                for(int k=i+i; k<=N; k+=i)
                    divisores[k]++;
        
        //System.out.println(Arrays.toString(divisores));
        
        almost = new LinkedList<Integer>();
        for(int i=2; i<=N; i++)
            if(divisores[i]==2) {
                //almost.add(i);
                numAlmost++;
            }
    }
}