import java.io.*;
import java.util.*;


public class Main_yukicoder516 {

	private static Scanner sc;
	private static Printer pr;

	private static void solve() {
		String[] s = new String[3];
		int r = 0;
		for (int i = 0; i < 3; i++) {
			s[i] = sc.next();
			if (s[i].equals("RED")) {
				r++;
			}
		}

		if (r > 1) {
			pr.println("RED");
		} else {
			pr.println("BLUE");
		}
	}

	// ---------------------------------------------------
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		pr = new Printer(System.out);

		solve();

		pr.close();
		sc.close();
	}

	private static class Printer extends PrintWriter {
		Printer(PrintStream out) {
			super(out);
		}
	}
}