def solve():

    S = eval(input())

    if S == "ABC":

        print("ARC")

    else:

        print("ABC")





if __name__ == '__main__':

    solve()

def solve():

    S = eval(input())

    if S == "ABC":

        print("ARC")

        exit()

    else:

        print("ABC")





if __name__ == '__main__':

    solve()

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


if __name__ == "__main__":
    solve()

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


if __name__ == "__main__":
    solve()

+        exit()