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