S = eval(input())

print(("ABC" if S == "ARC" else "ARC"))

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

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

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