# coding: utf-8
import array, bisect, collections, copy, heapq, itertools, math, random, re, string, sys, time
sys.setrecursionlimit(10 ** 7)
INF = 10 ** 20
MOD = 10 ** 9 + 7


def II(): return int(input())
def ILI(): return list(map(int, input().split()))
def IAI(LINE): return [ILI() for __ in range(LINE)]
def IDI(): return {key: value for key, value in ILI()}


def read():
    s1 = str(input())
    s2 = str(input())
    s3 = str(input())
    return (s1, s2, s3)

def solve(s1, s2, s3):
    data = [s1, s2, s3]
    count = collections.Counter(data)
    ans = ""
    if count["RED"] >= 2:
        ans = "RED"
    else:
        ans = "BLUE"
    return ans

def main():
    params = read()
    print(solve(*params))


if __name__ == "__main__":
    main()