S = eval(input())

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

S = eval(input())

if S == "ABC":

  print("ARC")

else:

  print("ABC")

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

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

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