using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

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

if (n < 0)

{

Console.WriteLine("Number too small");

Environment.Exit(0);

}

        else if (n > 32767)

{

Console.WriteLine("Number too large");

Environment.Exit(0);

}

        else

{

for (int f = n + 1; ; f++)

{

int c = 0;

for (int j = 1; j <= f; j++)

{

if (f % j == 0)

{

c++;

}

}if

(c == 2)

{

Console.WriteLine(f);

Console.ReadLine();

//Environment.Exit(0);

break;}

}

    }

}

}