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
//package hiougyf;
import java.io.*;
import java.util.*;

public class Solution {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		int a[]=new int[n+1];
		a[1]=1;
		
		for(int i=2;i<a.length;i++) {
			
				if(a[i]==0) {
					for(int j=i+i;j<a.length;j+=i) {
						a[j]++;
					}
				}
			
		}
	
		int ans=0;
		for(int i=1;i<=n;i++) {
			if(a[i]==2) {
				ans++;
			}
		}
		System.out.println(ans);
	}
    
	  public static int floorSqrt(int x) 
	    { 
	        // Base Cases 
	        if (x == 0 || x == 1) 
	            return x; 
	  
	        // Do Binary Search for floor(sqrt(x)) 
	        int start = 1, end = x, ans=0; 
	        while (start <= end) 
	        { 
	            int mid = (start + end) / 2; 
	  
	            // If x is a perfect square 
	            if (mid*mid == x) 
	                return mid; 
	  
	            // Since we need floor, we update answer when mid*mid is 
	            // smaller than x, and move closer to sqrt(x) 
	            if (mid*mid < x) 
	            { 
	                start = mid + 1; 
	                ans = mid; 
	            } 
	            else   // If mid*mid is greater than x 
	                end = mid-1; 
	        } 
	        return ans; 
	    } 
		static int div(int n,int b) {
			int g=-1;
			for(int i=2;i<=Math.sqrt(n);i++) {
				if(n%i==0&&i!=b) {
					g=i;
					break;
				}
			}
			return g;
		}
	 
	  
	  public static int gcd(int a, int b) 
	    { 
	        if (a == 0) 
	            return b; 
	          
	        return gcd(b%a, a); 
	    } 
	   public static int lcm(int a, int b)  
	  {  
	     return (a*b)/gcd(a, b);  
	  }  
	   public static boolean isPrime1(int n) {
           if (n <= 1) {
               return false;
           }
           if (n == 2) {
               return true;
           }
           for (int i = 2; i <= Math.sqrt(n) + 1; i++) {
               if (n % i == 0) {
                   return false;
               }
           }
           return true;
       }
       public static boolean isPrime(int n) {
           if (n <= 1) {
               return false;
           }
           if (n == 2) {
               return true;
           }
           if (n % 2 == 0) {
               return false;
           }
           for (int i = 3; i <= Math.sqrt(n) + 1; i = i + 2) {
               if (n % i == 0) {
                   return false;
               }
           }
           return true;
       }
	      
	
}

  
