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.Scanner;
/**
 * @author USER
 *
 */
public class AlmostPrime {

	/**
	 * @param args
	 */
	
	public static boolean isPrime(int num) {
		if(num<=1) {
			return false;
		}
		
		for(int i=2;i*i<=num;i++) {
			if(num%i==0) {
				return false;
			}
		}
		return true;
	}
	
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc=new Scanner(System.in);

		int num=sc.nextInt();
		int count=0, pcount=0;
		
		int n=0;
		
		if(num<6) {
			System.out.println("0");
			return;
		}
		
		for(int i=0; i<=num;i++) {
			
			for(int j=1;j<=n;j++) {
				if(n%j==0) {
					//약수일 경우, 소수인지 검사!
					if(isPrime(j)){
						count++;				
					}
				}
				
				//
			}
			if(count==2) {
				pcount++;
			}	
			
			count=0;
			
			n++;
		}
		System.out.println(pcount);

	}

}
