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.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.util.Vector;

public class T1 implements Runnable {

    public void metod() throws IOException {
        int n = nextInt();

        Vector<Integer> vc = new Vector<Integer>();
        for (int i = 2; i < 3001; i++) {
            if (pr(i)) {
                vc.add(i);
            }
        }
        int k = 0;
        for (int i = 1; i <= n; i++) {
            int h = 0;
            for (int j = 0; j < vc.size(); j++) {
                if (h > 2) {
                    break;
                } else {
                    if (i % vc.get(j) == 0) {
                        h++;
                    }
                }
            }
            if (h == 2) {
                k++;
            }
        }
        writer.println(k);
    }

    static boolean pr(int n) {
        if (n == 1) {
            return false;
        } else
            for (int i = 2; i < (int) Math.sqrt(n) + 1; i++) {
                if (n % i == 0) {
                    return false;
                }
            }
        return true;
    }

    static BufferedReader reader;
    static StringTokenizer tokenizer;
    static PrintWriter writer;

    public void run() {
        try {
            reader = new BufferedReader(new InputStreamReader(System.in));
            tokenizer = null;
            writer = new PrintWriter(System.out);
            metod();
            reader.close();
            writer.close();
        } catch (Exception e) {
            e.printStackTrace();
            System.exit(1);
        }
    }

    static int nextInt() throws IOException {
        return Integer.parseInt(nextToken());
    }

    static long nextLong() throws IOException {
        return Long.parseLong(nextToken());
    }

    static double nextDouble() throws IOException {
        return Double.parseDouble(nextToken());
    }

    static String nextToken() throws IOException {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            tokenizer = new StringTokenizer(reader.readLine());
        }
        return tokenizer.nextToken();
    }

    public static void main(String[] args) {
        new T1().run();
    }
}
