import java.util.Scanner;

public class Main {
    public static void main(String args[]) {
        Scanner scan = null;
        try {
            scan = new Scanner(System.in);
            String str = scan.nextLine();
            if (str != null && str.equals("ABC")) {
                System.out.println("ARC");
            } else {
                System.out.println("ABC");
            }
        } finally {
            scan.close();
        }
    }
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz