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.*;
 
public class Main{    
    //-----------MyScanner class for faster input----------------------------------
    public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;
 
        public MyScanner() throws FileNotFoundException {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
 
        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
 
        int nextInt() {
            return Integer.parseInt(next());
        }
 
        long nextLong() {
            return Long.parseLong(next());
        }
 
        double nextDouble() {
            return Double.parseDouble(next());
        }
 
        String nextLine(){
            String str="";
            try {
                str =  br.readLine().toString();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
 
    }
    //----------------------------------------------------------------------------
    
    public static void main(String[] args) throws FileNotFoundException {
       
 
        MyScanner sc = new MyScanner();   // Use MyScanner class.
                                          // The constructor MyScanner() has no argument
                                          // as opposed to Scanner(System.in)!
         int n = sc.nextInt();
         int[] arr = new int[n+1];
         int[] rem = new int[n+1];
         int count = 0;
         for(int i=0;i<rem.length;i++) rem[i]=i;
         
         for(int i=2;i<arr.length;i++) {
             for(int j=i+1;j<arr.length;j++) {
                 int t = rem[j];
                 if(t == 0 ) continue;
                 while( t%i == 0) {
                     t = t/i;
                 }
                 if(rem[j]%i == 0) { 
                     rem[j] = t; 
                     arr[j]++;
                     if(rem[j] == 1 && arr[j] == 2) count++;
                 }                
             }
         }
      /*   for(int i=0;i<arr.length;i++) System.out.print(i + " "); 
         System.out.println();
         
         for(int i=0;i<arr.length;i++) System.out.print(arr[i] + " "); 
         System.out.println();
         
         for(int i=0;i<rem.length;i++) System.out.print(rem[i] + " ");*/         
         System.out.println(count);
         
    }
}