using System;

using System.Collections;

using System.Linq;

public class Program

{

    public static void Main()

    {

        Random random = new Random();

        const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz";

        Console.WriteLine(new string(Enumerable.Repeat(chars, 7).Select(s => s[random.Next(s.Length)]).ToArray()) + "-" + new string(Enumerable.Repeat(chars, 4).Select(s => s[random.Next(s.Length)]).ToArray()));

    }

}