using System;

using System.Linq;

public class A

{

    public static void Main()

    {

        int k = int.Parse(Console.ReadLine());

        var p = Enumerable.Range(2, 33500)

            .Where(x =>

            {

                // Checking that x is a prime number

                for (int i = 2; i < x; i++)

                    if (x % i == 0)

                        return false;

                return true;

            })

            .ToArray();

        // From prime numbers whose ordinal number is a prime number, take the k-th number

        Console.Write(p.Where((_, i) => p.Contains(i + 1)).Take(k).Last());

    }

}