import java.util.Scanner;

public class Main{
	public static void main(String[]org){
    	
      Scanner scan = new Scanner(System.in);
      String s = scan.nextLine();
      String result = "";
      if(s.charAt(1)=='B'){
		result = "ARC";
      }
      else{
        result ="ABC";
      }
     System.out.println(result);
	}
} import java.util.Scanner; Scanner java.util public class Main{
	public static void main(String[]org){
    	
      Scanner scan = new Scanner(System.in);
      String s = scan.nextLine();
      String result = "";
      if(s.charAt(1)=='B'){
		result = "ARC";
      }
      else{
        result ="ABC";
      }
     System.out.println(result);
	}
} Main public static void main(String[]org){
    	
      Scanner scan = new Scanner(System.in);
      String s = scan.nextLine();
      String result = "";
      if(s.charAt(1)=='B'){
		result = "ARC";
      }
      else{
        result ="ABC";
      }
     System.out.println(result);
	} main {
    	
      Scanner scan = new Scanner(System.in);
      String s = scan.nextLine();
      String result = "";
      if(s.charAt(1)=='B'){
		result = "ARC";
      }
      else{
        result ="ABC";
      }
     System.out.println(result);
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String s = scan.nextLine(); s scan.nextLine() scan.nextLine scan String result = ""; result "" if(s.charAt(1)=='B'){
		result = "ARC";
      }
      else{
        result ="ABC";
      } s.charAt(1)=='B' s.charAt(1) s.charAt s 1 'B' {
		result = "ARC";
      } result = "ARC" result "ARC" {
        result ="ABC";
      } result ="ABC" result "ABC" System.out.println(result) System.out.println System.out System System.out result String[]org org public class Main{
	public static void main(String[]org){
    	
      Scanner scan = new Scanner(System.in);
      String s = scan.nextLine();
      String result = "";
      if(s.charAt(1)=='B'){
		result = "ARC";
      }
      else{
        result ="ABC";
      }
     System.out.println(result);
	}
} public class Main{
	public static void main(String[]org){
    	
      Scanner scan = new Scanner(System.in);
      String s = scan.nextLine();
      String result = "";
      if(s.charAt(1)=='B'){
		result = "ARC";
      }
      else{
        result ="ABC";
      }
     System.out.println(result);
	}
} Main
import java.util.Scanner;

public class Main{
	public static void main(String[]org){
    	
      Scanner scan = new Scanner(System.in);
      String s = scan.nextLine();
      String result = "";
      if(s.charAt(1)=='B'){
		result = "ARC";
      }
      else{
        result ="ABC";
      }
     System.out.println(result);
	}
}
