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.File;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.Arrays;
import java.util.Scanner;

public class Main {

	/**
	 * @param args
	 */

	public static void main(String[] args) throws Exception {
		Main task = new Main();
		task.run();

	}

	Scanner inp;
	PrintWriter out;
int[] notpr;
	int[] sundaram(int n) {
		int count = n;

		int[] a = new int[n + 1];
		int i, j;
		a[0] = 0;
		a[1] = 1;
		for (i = 2; i<=n;i++)
			for (j=i+1;j<=n;j++)
				if ((j%i==0))a[j] = 1;
		j = 0;
		int d = 0;
		notpr = new int[n];
		int[] ans = new int[count-1];
		for (i = 1; i < n; i++) {
			if (a[i] == 0) {
				ans[j] = i;
				j++;
			}
			else
			{
				notpr[d] = i;
				d++;
			}
			
		}
		return ans;
	}

	private void run() throws Exception {
		inp = new Scanner(System.in);
		out = new PrintWriter(System.out);
		int n = inp.nextInt();
		//if (n<6) {out.print(0); out.close();System.exit(0);}
		int[] spis = sundaram(n);
		int c = spis.length;
		int ans = 0;
		for (int i =1;i<=n;i++)
		{
			int cc = 0;
			for (int j = 0;j<c;j++)
				if (spis[j]!=0) if (i%spis[j]==0)cc++;
			if (cc==2) ans++;
		}
		out.print(ans);

		inp.close();
		out.close();

	}

}