//
//  main.swift
//  AtCoder
//
//  Copyright © 2020 dazy. All rights reserved.
//

import Foundation

func rl() -> String {
    readLine()!
}

func rls() -> [String] {
    readLine()!.components(separatedBy: " ")
}

let s = rl()
print(s == "ABC" ? "ARC" : "ABC")
