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.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.InputMismatchException;
import java.util.LinkedList;
import java.util.Map;
import java.util.Queue;
import java.util.Stack;
import java.util.StringTokenizer;


/**
 *
 * @author Kayali
 */
public class Aday {
   
  static int  gcd(int x, int y) {
            if (Integer.min(x, y) == 0) return x + y;
            return gcd(y, x % y);
        }
 
        
    public static void main(String[] args) throws Exception {
       FastReader in = new FastReader();
       PrintWriter pw = new PrintWriter(System.out);
       
        int n=in.nextInt();
            
        int arr[]=new int[3001];
        Arrays.fill(arr,0);
        
        for(int i=2;i<3001;i++){
            if(arr[i]==0)
                for(int j=i*2;j<3001;j+=i)
                    arr[j]++;
        }
        
        int cnt=0;
        for(int i=6;i<=n;i++){
            if(arr[i]==2){
                cnt++;
            }
        }
        pw.println(cnt);
     
        
        pw.flush();
     pw.close();
        
        
        
        
        
        
    }
   static class FastReader {
 
        StringTokenizer st;
        BufferedReader br;
 
        public FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
 
        public String next() throws IOException {
            if (st == null || !st.hasMoreTokens()) {
                st = new StringTokenizer(br.readLine());
            }
            return st.nextToken();
        }
 
        public boolean hasNext() throws IOException {
            if (st != null && st.hasMoreTokens()) {
                return true;
            }
            String s = br.readLine();
            if (s == null || s.isEmpty()) {
                return false;
            }
            st = new StringTokenizer(s);
            return true;
        }
 
        public int nextInt() throws IOException {
            return Integer.parseInt(next());
        }
 
        public long nextLong() throws IOException {
            return Long.parseLong(next());
        }
 
        public double nextDouble() throws IOException {
            return Double.parseDouble(next());
        }
 
        public String nextLine() throws IOException {
            return br.readLine();
        }
    }
   
   
}
