
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		String str=scan.nextLine();

		if(str.equals("ABC")) {

			//S=ABC then the output is ARC
			System.out.println("ARC");

		}else if(str.equals("ARC")) {

			//S=ARC then the output is ABC
			System.out.println("ABC");

		}else{

			System.out.println("Incorrect input");

		}

		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