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.math.BigInteger;
import java.util.*;

public class CodeForces {

	public static void main(String[] args) throws IOException,NumberFormatException{
		try {
			FastScanner sc=new FastScanner();
			int n=sc.nextInt();
			int count=0;
			for(int i=6;i<=n;i++) {
				if(isAlmostPrime(i)) {
					count++;
				}
			}
			System.out.println(count);
			
		}
		catch(Exception e) {
			return ;
		}

	}
	public static boolean isAlmostPrime(int n) {
		int count=0;
		for(int i=2;i*i<=n;i++) {
			if(n%i==0) {
				count++;
				while(n%i==0) {
					n/=i;
				}
			}
		}
		if(n>1)
			count++;
		if(count==2)
			return true;
		else 
			return false;
	}
	
	public static class FastScanner {
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st=new StringTokenizer("");
		String next() {
			while (!st.hasMoreTokens())
				try { 
                                      st=new StringTokenizer(br.readLine());				               
                              } catch (IOException e) {}
			return st.nextToken();
		}
		
		int nextInt() {
			return Integer.parseInt(next());
		}
		long nextLong() {
			return Long.parseLong(next());
		}
		
	}
}