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.HashSet;
import java.util.Set;
import java.util.StringTokenizer;
// نورت الكود يا كبير اتفضل

// يا رب Accepted
public class AlmostPrime {

    public static boolean almostPrime(int n) {
        Set<Integer> set = new HashSet<>();
        while (n % 2 == 0) {
            set.add(2);
            n /= 2;
        }

        for (int i = 3; i * i <= n; i += 2) {
            while (n % i == 0) {
                set.add(i);
                n /= i;
            }
        }

        if (n > 2)
            set.add(n);
        return set.size() == 2;
    }

    public static void main(String[] args) {
        FastReader in = new FastReader();
        PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out));

        int n = in.nextInt();

        int res = 0;
        for (int i = 6; i <= n; i++)
            if (almostPrime(i))
                res++;

        out.println(res);

        out.close();
    }

    private static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        FastReader() {
            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());
        }
    }
}