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.*;
import java.io.*;
import java.math.BigInteger;

public class _practise {

	public static long sum(long a[])
	{
		long sum=0;
		for(long i : a) sum+=i;
		return(sum);
	}
	public static int sum(int a[])
	{
		int sum=0;
		for(int i : a) sum+=i;
		return(sum);
	}
	public static boolean prime(int n)
	{
		for(int i=2 ; i<=n/2 ; i++)
			if(n%i==0)
			{
				return false;
			}
		return true;
	}
	public static void main(String args[])
	{

		FastReader in=new FastReader();
		PrintWriter so = new PrintWriter(new BufferedWriter(new  OutputStreamWriter(System.out)));
		_practise ob = new _practise();
		//int t = in.nextInt();
		int t = 1;
		while(t-->0)
		{
		   int n =in.nextInt();
		   int ans=0;
		   for(int i=6 ; i<=n ; i++)
		   {
			   
			   Set<Integer> al = new HashSet<Integer>();
			   int c=0;
			   for(int j=2 ; j<=i/2 ; j++)
			   {
				  if(i%j==0)
					  {
					  al.add(j);
					  if(i/j!=j)
					  al.add(i/j);
					  }
			   }
			   al.add(i);
			   for(int j  : al)
			   {
				//   so.print(j+" ");
				   if(prime(j)) c++;
			   }
			 //  so.println();
			   if(c==2) ans++;
		   }
		   so.println(ans);
		}
		
		so.flush();

		/*String s = in.next();
		 * Arrays.stream(f).min().getAsInt()
		 * BigInteger f = new BigInteger("1"); 1 ke jagah koi bhi value ho skta jo aap 
		 *                                       initial value banan chahte
			int a[] = new int[n];
			ArrayList<Integer> al = new ArrayList<Integer>(); 
			StringBuilder sb = new StringBuilder();
			Set<Long> a = new HashSet<Long>();
			Map<Long,Integer> hm = new HashMap<Long, Integer>(); //<key,value>
			HashMap<Integer, Integer> hmap = new HashMap<Integer, Integer>();
			so.println("HELLO");*/
	}

	static class FastReader
	{ 
		BufferedReader br; 
		StringTokenizer st; 

		public FastReader() 
		{ 
			br = new BufferedReader(new InputStreamReader(System.in)); 
		} 

		String next() 
		{ 
			while (st == null || !st.hasMoreElements()) 
			{ 
				try
				{ 
					st = new StringTokenizer(br.readLine()); 
				} 
				catch (IOException  e) 
				{ 
					e.printStackTrace(); 
				} 
			} 
			return st.nextToken(); 
		} 

		int nextInt() 
		{ 
			return Integer.parseInt(next()); 
		} 

		long nextLong() 
		{ 
			return Long.parseLong(next()); 
		} 

		double nextDouble() 
		{ 
			return Double.parseDouble(next()); 
		} 

		 int[] ia(int n)
		{
			int a[]=new int[n];
			for(int i=0;i<n;i++)a[i]=nextInt();
			return a;
		}
		 int[][] ia(int n , int m)
			{
				int a[][]=new int[n][m];
				for(int i=0;i<n;i++) for(int j=0;j<n ;j++) a[i][j]=nextInt();
				return a;
			}
		 char[][] ca(int n , int m)
			{
				char a[][]=new char[n][m];
				for(int i=0;i<n;i++)
					{
					String x =next();
					for(int j=0;j<n ;j++) a[i][j]=x.charAt(j);
					}
				return a;
			}

		long[] la(int n)
		{
			long a[]=new long[n];
			for(int i=0;i<n;i++)a[i]=nextLong();
			return a;
		}

		String nextLine() 
		{ 
			String str = ""; 
			try
			{ 
				str = br.readLine(); 
			} 
			catch (IOException e) 
			{ 
				e.printStackTrace(); 
			} 
			return str; 
		} 
	} 
}