public class Program
{
    public static void Main()
    {
        //int num = int.Parse(Console.ReadLine() ?? string.Empty);
        //string[] str = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');
        string str = Console.ReadLine() ?? string.Empty;
        string str2 = Console.ReadLine() ?? string.Empty;
        string str3 = Console.ReadLine() ?? string.Empty;


        string ss = str+str2 + str3;
        int count = 0;
        while(ss.Length > 0)
        {
            if (ss.IndexOf('R') == 0)
            {
                count++;
                ss = ss.Remove(0, 3);
            }
            else
            {
                ss = ss.Remove(0, 4);
                count--;
            }
        }
        if(count > 0)
        {
            Console.WriteLine("RED");
        }
        else
        {
            Console.WriteLine("BLUE");
        }
    }
}