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.OutputStreamWriter;
import java.io.BufferedWriter;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.Writer;
import java.util.List;
import java.io.IOException;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.ArrayList;
import java.util.NoSuchElementException;
import java.math.BigInteger;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author Alex
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		OutputWriter out = new OutputWriter(outputStream);
		TaskA solver = new TaskA();
		solver.solve(1, in, out);
		out.close();
	}
}

class TaskA {
    public boolean twodivisors(int x){
        List<Pair<Long, Integer>> res = IntegerUtils.factorize(x);
        if (res.size() == 2) return true;
        return false;
    }

    public void solve(int testNumber, InputReader in, OutputWriter out) {
        int n = in.readInt();
        int res = 0;
        for (int i = 1; i <= n; i++) {
            if (twodivisors(i)) res++;
        }
        out.print(res);
    }
}

class Pair<U, V> implements Comparable<Pair<U, V>> {
	public final U first;
	public final V second;

	public static<U, V> Pair<U, V> makePair(U first, V second) {
		return new Pair<U, V>(first, second);
	}

	private Pair(U first, V second) {
		this.first = first;
		this.second = second;
	}

	public boolean equals(Object o) {
		if (this == o) return true;
		if (o == null || getClass() != o.getClass()) return false;

		Pair pair = (Pair) o;

		return !(first != null ? !first.equals(pair.first) : pair.first != null) && !(second != null ? !second.equals(pair.second) : pair.second != null);

	}

	public int hashCode() {
		int result = first != null ? first.hashCode() : 0;
		result = 31 * result + (second != null ? second.hashCode() : 0);
		return result;
	}
	public String toString() {
		return "(" + first + "," + second + ")";
	}

	public int compareTo(Pair<U, V> o) {
		int value = ((Comparable<U>)first).compareTo(o.first);
		if (value != 0)
			return value;
		return ((Comparable<V>)second).compareTo(o.second);
	}
}

class IntegerUtils {
	public static List<Pair<Long, Integer>> factorize(long number) {
		List<Pair<Long, Integer>> result = new ArrayList<Pair<Long, Integer>>();
		for (long i = 2; i * i <= number; i++) {
			if (number % i == 0) {
				int power = 0;
				do {
					power++;
					number /= i;
				} while (number % i == 0);
				result.add(Pair.makePair(i, power));
			}
		}
		if (number != 1)
			result.add(Pair.makePair(number, 1));
		return result;
	}
}

class InputReader {
	private InputStream stream;
	private byte[] buf = new byte[1024];
	private int curChar;
	private int numChars;
	private SpaceCharFilter filter;

	public InputReader(InputStream stream) {
		this.stream = stream;
	}

	public int read() {
		if (numChars == -1)
			throw new InputMismatchException();
		if (curChar >= numChars) {
			curChar = 0;
			try {
				numChars = stream.read(buf);
			} catch (IOException e) {
				throw new InputMismatchException();
			}
			if (numChars <= 0)
				return -1;
		}
		return buf[curChar++];
	}
	public int readInt() {
		int c = read();
		while (isSpaceChar(c))
			c = read();
		int sgn = 1;
		if (c == '-') {
			sgn = -1;
			c = read();
		}
		int res = 0;
		do {
			if (c < '0' || c > '9')
				throw new InputMismatchException();
			res *= 10;
			res += c - '0';
			c = read();
		} while (!isSpaceChar(c));
		return res * sgn;
	}
	public boolean isSpaceChar(int c) {
		if (filter != null)
			return filter.isSpaceChar(c);
		return isWhitespace(c);
	}

	public static boolean isWhitespace(int c) {
		return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
	}
	public interface SpaceCharFilter {
		public boolean isSpaceChar(int ch);
	}
}

class OutputWriter {
	private final PrintWriter writer;

	public OutputWriter(OutputStream outputStream) {
		writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
	}
	public void close() {
		writer.close();
	}
	public void print(int i) {
		writer.print(i);
	}
}

