import java.util.Scanner;

/**
 * @author hellb
 *
 */
public class Main {

	private static String ARC = "ARC";

	private static String ABC = "ABC";

	/**
	 * @param args
	 */
	public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);
        String sNum1 = scan.next();
        String sResult;
        scan.close();

        if (ARC.equals(sNum1)) {
        	sResult = ABC;
        } else {
        	sResult = ARC;
        }
        System.out.print(sResult);
	}
} import java.util.Scanner; Scanner java.util public class Main {

	private static String ARC = "ARC";

	private static String ABC = "ABC";

	/**
	 * @param args
	 */
	public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);
        String sNum1 = scan.next();
        String sResult;
        scan.close();

        if (ARC.equals(sNum1)) {
        	sResult = ABC;
        } else {
        	sResult = ARC;
        }
        System.out.print(sResult);
	}
} Main private static String ARC = "ARC"; ARC "ARC" private static String ABC = "ABC"; ABC "ABC" /**
	 * @param args
	 */
	public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);
        String sNum1 = scan.next();
        String sResult;
        scan.close();

        if (ARC.equals(sNum1)) {
        	sResult = ABC;
        } else {
        	sResult = ARC;
        }
        System.out.print(sResult);
	} main {

        Scanner scan = new Scanner(System.in);
        String sNum1 = scan.next();
        String sResult;
        scan.close();

        if (ARC.equals(sNum1)) {
        	sResult = ABC;
        } else {
        	sResult = ARC;
        }
        System.out.print(sResult);
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String sNum1 = scan.next(); sNum1 scan.next() scan.next scan String sResult; sResult scan.close() scan.close scan if (ARC.equals(sNum1)) {
        	sResult = ABC;
        } else {
        	sResult = ARC;
        } ARC.equals(sNum1) ARC.equals ARC sNum1 {
        	sResult = ABC;
        } sResult = ABC sResult ABC {
        	sResult = ARC;
        } sResult = ARC sResult ARC System.out.print(sResult) System.out.print System.out System System.out sResult String[] args args public class Main {

	private static String ARC = "ARC";

	private static String ABC = "ABC";

	/**
	 * @param args
	 */
	public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);
        String sNum1 = scan.next();
        String sResult;
        scan.close();

        if (ARC.equals(sNum1)) {
        	sResult = ABC;
        } else {
        	sResult = ARC;
        }
        System.out.print(sResult);
	}
} public class Main {

	private static String ARC = "ARC";

	private static String ABC = "ABC";

	/**
	 * @param args
	 */
	public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);
        String sNum1 = scan.next();
        String sResult;
        scan.close();

        if (ARC.equals(sNum1)) {
        	sResult = ABC;
        } else {
        	sResult = ARC;
        }
        System.out.print(sResult);
	}
} Main
import java.util.Scanner;

/**
 * @author hellb
 *
 */
public class Main {

	private static String ARC = "ARC";

	private static String ABC = "ABC";

	/**
	 * @param args
	 */
	public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);
        String sNum1 = scan.next();
        String sResult;
        scan.close();

        if (ARC.equals(sNum1)) {
        	sResult = ABC;
        } else {
        	sResult = ARC;
        }
        System.out.print(sResult);
	}
}
