import java.util.Scanner;
public class Main
{
  public static void main ( String [ ] args)
  {
    Scanner scanner = new Scanner(System.in);
    System.out.println("Enter an integer greater than 1");
    int n = scanner.nextInt();
    int composites = 1;
    int[] nums = new int[n+1];
    for(int i = 0; i <= n; i++)
    {
      nums[i] = i;
    }
    for(int i = 2; i <= (Math.sqrt(n) + 1); i++)
    {
      for(int j = i*2; j <= n; j+=i)
      {
        if(nums[j] != 0)
        {
          nums[j] = 0;
          composites++;
        }
      }
    }
      if(nums[n] != 0) composites++;
      System.out.println("There are " + (n - composites) + " prime numbers below " + n);
      scanner.close();
  }
}