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.BufferedReader;
import java.io.PrintWriter;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.Collection;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;

public class CF26A implements Runnable{
        
    public static void main(String args[]){
       new CF26A().run();
    }
    
    @Override
    public void run(){
        try{
            in = new BufferedReader(new InputStreamReader(System.in));
            out = new PrintWriter(System.out);
            tok = null;
            solve();
            in.close();
            out.close();
            
        }
        catch(IOException e){
            e.printStackTrace();
            System.exit(0);
        }
    }
    
    int nextInt()throws IOException{
        return Integer.parseInt(nextToken());
    } 
    
    double nextDouble()throws IOException{
        return Double.parseDouble(nextToken());
    }
    
    long nextLong() throws IOException{
        return Long.parseLong(nextToken());
    }
    
    String nextToken()throws IOException{
        while(tok == null || !tok.hasMoreTokens()){
            tok = new StringTokenizer(in.readLine());
        }
        return tok.nextToken();
    }
    
    BufferedReader in;
    PrintWriter out;
    StringTokenizer tok;
    //////////////////////////////////////////////////////////////////
    //////////////////////////////////////////////////////////////////
    private void solve()throws IOException{
      int[] prime = new int[3001];
      for(int i = 2; i < 3001; i++){
          if(prime[i] != 0) continue;
          for(int j = i; j < 3001; j += i)
              prime[j]++;
      }
      
      int n = nextInt();
      int ans  = 0;
      for(int i = 1; i <= n; i++){
          if(prime[i] == 2) ans++;
      } 
      out.println(ans);
    }
}

