import java.util.Scanner;
public class Main {

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

} import java.util.Scanner; Scanner java.util public class Main {

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

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

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

} public class Main {

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

} Main
import java.util.Scanner;
public class Main {

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

}
