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.util.*;
import java.io.*;
public class codeforces {
    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public 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());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
    static boolean[] sieve(int N) {
        boolean[] prime = new boolean[N + 1];
        Arrays.fill(prime, true);
        prime[0] = false;
        prime[1] = false;
        for (int i = 2; i * i <= N; ++i) {
            if (prime[i]) {
                for (int j = i * i; j <= N; j += i)
                    prime[j] = false;
            }
        }
        return prime;
    }

        public static void main(String[] args) {
            FastReader sc = new FastReader();
            int n = sc.nextInt();
            int i,j,c=0,res=0;
            boolean[] prime;
            prime=sieve(n);
            for(i=1;i<=n;i++)
            {
                for(j=2;j<n+1;j++)
                {
                    if(prime[j])
                    {
                        if(i%j==0)
                            c++;
                    }
                }
                if(c==2)
                    res++;
                c=0;
            }
            System.out.println(res);
        }

    }






