s = eval(input())



if s == "ABC":

    print("ARC")

else:

    print("ABC")

import sys

read = sys.stdin.buffer.read

readline = sys.stdin.buffer.readline

readlines = sys.stdin.buffer.readlines



s = read().rstrip().decode()



if s == "ABC":

    print("ARC")

else:

    print("ABC")

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

import sys

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
s = read().rstrip().decode()
if s == "ABC":
    print("ARC")
else:
    print("ABC")

-s = eval(input()) +import sys + +read = sys.stdin.buffer.read +readline = sys.stdin.buffer.readline +readlines = sys.stdin.buffer.readlines +s = read().rstrip().decode()