//
//  main.swift
//  readLine
//
//  Created by MAC on 5/4/20.
//  Copyright © 2020 Ahliddin Akhmedov. All rights reserved.
//

import Foundation

//print("Enter how many days you will swim, bike or run this week?")
//
//var numberOfDays = Int(readLine() ?? "-1") ?? -1
//
//print("you entered \(numberOfDays + 10)")
//
//// command + r => builds and run the application
//// command + b => only builds and checks for errors
//
//var a = Int(readLine()!)!
//var b : [Int] = []
//
//
//
//var s : Int = 0
//var c : Int = 0
//
//for i in b {
//    if i == 10{
//        s += 1
//    } else{
//        c += 1
//    }
//}
//print("s - \(s), c- \(c)")

var str = readLine()
if str == "ARC" {
    print("ABC")
} else{
    print("ARC")
}




