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