S = eval(input())

print(('ABC' if S == 'ARC' else 'ARC'))
s = eval(input())

print(('ABC' if s == 'ARC' else 'ARC'))
S = eval(input())
print(("ABC" if S == "ARC" else "ARC"))

s = eval(input())
print(("ABC" if s == "ARC" else "ARC"))

-S = eval(input()) -print(("ABC" if S == "ARC" else "ARC")) +s = eval(input()) +print(("ABC" if s == "ARC" else "ARC"))