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.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.sql.SQLOutput;
import java.util.*;
import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
    static void bin(int n) {
        if (n > 1)
            bin(n/2);

        System.out.print(n % 2);
    }
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.solve(1, in, out);
        out.close();
    }
    static class Pair<a , b>{
        a v1;
        b v2;
        Pair(a v1 , b v2){
            this.v1 = v1;
            this.v2 = v2;
        }
    }
    static class TaskA {
        static int lastdigit(int a){
            while (a/10>0){
                a/=10;
            }
            return a%10;

        }
        static boolean ok(int a){
            int fac = 0;
            if (a%2 == 0){
                fac++;
                while (a%2 == 0) a/=2;
            }
            for (int i = 3; i <=Math.sqrt(a); i+=2){
                if (a%i == 0){
                    fac++;
                    if (fac> 2) return false;
                    while (a%i == 0) a/=i;
                }
            }
            if (a > 1) fac++;
            return (fac ==2);
        }
        public void solve(int testNumber, InputReader in, PrintWriter out){
            int n = in.nextInt();
            int ans = 0;
            for (int i = 2; i <=n; i++) {
                if (ok(i))ans++;
            }
            System.out.println(ans);



        }

    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }
        public int nextInt(){return  Integer.parseInt(next());}
        public long nextLong() {
            return Long.parseLong(next());
        }

    }
}