import java.util.Scanner;

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

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

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

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

} Main
import java.util.Scanner;

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

}
