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.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class Problem {
	public static void main(String[] arg) {
		FastScanner scan = new FastScanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		int n = scan.nextInt();
		
		boolean[] prime = new boolean[3001];
		for(int i = 2; i < 3001; i++)prime[i] = true;
		for(int i = 2; i < 3001; i++){
			for(int j = 2; i * j < 3001; j++){
				prime[i * j] = false;
			}
		}
		int[] cnt = new int[n+1];
		for(int i = 2; i <= n; i++){
			if(!prime[i]) continue;
			for(int j = 1; i * j <= n; j++)
				cnt[i * j]++;
		}
		int ret = 0;
		for(int i = 2; i <= n; i++){
			if(cnt[i] == 2) ret++;
		}
		out.println(ret);
		out.close();
	}
	
	
	static class FastScanner {
		BufferedReader br;
		StringTokenizer st;

		FastScanner(InputStream is) {
			try {
				br = new BufferedReader(new InputStreamReader(is));
			} catch (Exception e) {
				e.printStackTrace();
			}
		}

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

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

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

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