using System;

public class Program

{

    public static bool isprime(int num)

    {

        int counter=0;

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

        {

            if(num%i==0)

            {

                counter++;

            }

        }

        if(counter==0)

        {

            return true;

        }

        else

        {

            return false;

        }

    }

    public static void Main()

    {

        int n,num=1,count=0;

        n=Convert.ToInt32(Console.ReadLine());

        while(true)

        {

            ++num;

            if(isprime(num))

            {

                count++;

                if(count==n)

                {

                    Console.Write(num);

                    break;

                }

            }

        }

    }

}