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.*;
public class Almost_Primes {
	
	static int LIM = 3001; 

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		Scanner s = new Scanner(System.in);
		
		int n = s.nextInt();
		int[] prime_factors = new int[LIM];
		
		for(int i=2;i<LIM;i++) {
			if(prime_factors[i]==0) {
				for(int j=i*2; j<LIM; j+=i) {
					prime_factors[j]+=1;
				}
			}
		}
		
		int res=0;
		for(int i=0; i<=n;i++) {
			if(prime_factors[i]==2)
				res+=1;
		}
		
		System.out.println(res);
		
		//displayRawArr(prime_factors);
		
		

	}
	
static void displayRawArr(int[] arr) {
		
		for(int i=0; i<arr.length; i++) {
			System.out.print(arr[i]+", ");
		}
		System.out.println();
	}

}




