import sys
from itertools import accumulate
from collections import Counter

def solve():
    s1 = input()
    s2 = input()
    s3 = input()

    if s1 == s2 == 'RED' or s1 == s3 == 'RED' or s2 == s3 == 'RED':
        print('RED')
    else:
        print('BLUE')

if __name__ == '__main__':
    solve()