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

/**
 * @author ViSioN
 *
 */
import java.util.*;
public class hi {
	public static boolean prime(int a){
		for(int i = 2; i <= a/2; i++){
			if(a%i==0)
				return false;
		}
		return true;
	}
	public static boolean almost(int x){
		int c = 0;
		for(int i = 2; i <= x/2; i++){
			if(x%i == 0){
				if(prime(i))
					c++;
			}
		}
		if(c == 2)
			return true;
		else
			return false;
	}
	public static void count(int z){
		int numbs = 0;
		for(int i = 1; i <= z; i++){
			if(almost(i))
				numbs++;
		}
		System.out.println(numbs);
	}
	public static void main(String[]args){
		Scanner in = new Scanner(System.in);
		int x = in.nextInt();
		count(x);
	}
}
