import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		String ABC = "ABC";
		String ARC = "ARC";
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		if (ABC.equals(s)) {
			System.out.println(ARC);
		} else {
			System.out.println(ABC);
		}
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		String ABC = "ABC";
		String ARC = "ARC";
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		if (ABC.equals(s)) {
			System.out.println(ARC);
		} else {
			System.out.println(ABC);
		}
	}
} Main public static void main(String[] args) {
		String ABC = "ABC";
		String ARC = "ARC";
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		if (ABC.equals(s)) {
			System.out.println(ARC);
		} else {
			System.out.println(ABC);
		}
	} main {
		String ABC = "ABC";
		String ARC = "ARC";
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		if (ABC.equals(s)) {
			System.out.println(ARC);
		} else {
			System.out.println(ABC);
		}
	} String ABC = "ABC"; ABC "ABC" String ARC = "ARC"; ARC "ARC" Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String s = sc.next(); s sc.next() sc.next sc if (ABC.equals(s)) {
			System.out.println(ARC);
		} else {
			System.out.println(ABC);
		} ABC.equals(s) ABC.equals ABC s {
			System.out.println(ARC);
		} System.out.println(ARC) System.out.println System.out System System.out ARC {
			System.out.println(ABC);
		} System.out.println(ABC) System.out.println System.out System System.out ABC String[] args args public class Main {
	public static void main(String[] args) {
		String ABC = "ABC";
		String ARC = "ARC";
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		if (ABC.equals(s)) {
			System.out.println(ARC);
		} else {
			System.out.println(ABC);
		}
	}
} public class Main {
	public static void main(String[] args) {
		String ABC = "ABC";
		String ARC = "ARC";
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		if (ABC.equals(s)) {
			System.out.println(ARC);
		} else {
			System.out.println(ABC);
		}
	}
} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		String ABC = "ABC";
		String ARC = "ARC";
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		if (ABC.equals(s)) {
			System.out.println(ARC);
		} else {
			System.out.println(ABC);
		}
	}
}