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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.StringTokenizer;


public class AlmostPrime {
	public static int t =0 ;
	public static BufferedReader in;
	public static StringTokenizer st;
	
	public static String nextToken() throws IOException {
		while (st == null || !st.hasMoreTokens()) st = new StringTokenizer(in.readLine());
		return st.nextToken();
	}
	
	public static int nextInt() throws IOException {
		return Integer.parseInt(nextToken());
	}
	
	public static void main(String [] args) throws Exception 
	{
		in = new BufferedReader(new InputStreamReader(System.in));
		int n = nextInt();
		boolean [] a  = new boolean[n+1];
		Arrays.fill(a,true);
		
		a[0]= false;
		a[1] = false;
		for(int i=2;i<n;i++){
						for(int j=2;i*j<n;j++)
						{
							a[i*j]= false;
						}
		}
						
						int res=0;
						for(int k=1;k<=n;k++)
						{	
							int s=0;
							for(int l=1;l<k;l++)
							{
									if(a[l])
									{
										if(k%l==0) {s++;}
									}
									
							}
							if(s==2) { res++;}
						}	
			
		System.out.println(res);
		
	}
}