import java.util.Scanner;

public class Main
{
	public static void main(String[] args)
	{
		Scanner sc = new Scanner(System.in);
		String str = sc.nextLine();
		sc.close();
		String ans = "ARC";
		if (str.compareTo(ans) == 0) {
			ans = "ABC";
		}
		System.out.println(ans);
	}
} import java.util.Scanner; Scanner java.util public class Main
{
	public static void main(String[] args)
	{
		Scanner sc = new Scanner(System.in);
		String str = sc.nextLine();
		sc.close();
		String ans = "ARC";
		if (str.compareTo(ans) == 0) {
			ans = "ABC";
		}
		System.out.println(ans);
	}
} Main public static void main(String[] args)
	{
		Scanner sc = new Scanner(System.in);
		String str = sc.nextLine();
		sc.close();
		String ans = "ARC";
		if (str.compareTo(ans) == 0) {
			ans = "ABC";
		}
		System.out.println(ans);
	} main {
		Scanner sc = new Scanner(System.in);
		String str = sc.nextLine();
		sc.close();
		String ans = "ARC";
		if (str.compareTo(ans) == 0) {
			ans = "ABC";
		}
		System.out.println(ans);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String str = sc.nextLine(); str sc.nextLine() sc.nextLine sc sc.close() sc.close sc String ans = "ARC"; ans "ARC" if (str.compareTo(ans) == 0) {
			ans = "ABC";
		} str.compareTo(ans) == 0 str.compareTo(ans) str.compareTo str ans 0 {
			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 sc = new Scanner(System.in);
		String str = sc.nextLine();
		sc.close();
		String ans = "ARC";
		if (str.compareTo(ans) == 0) {
			ans = "ABC";
		}
		System.out.println(ans);
	}
} public class Main
{
	public static void main(String[] args)
	{
		Scanner sc = new Scanner(System.in);
		String str = sc.nextLine();
		sc.close();
		String ans = "ARC";
		if (str.compareTo(ans) == 0) {
			ans = "ABC";
		}
		System.out.println(ans);
	}
} Main
import java.util.Scanner;

public class Main
{
	public static void main(String[] args)
	{
		Scanner sc = new Scanner(System.in);
		String str = sc.nextLine();
		sc.close();
		String ans = "ARC";
		if (str.compareTo(ans) == 0) {
			ans = "ABC";
		}
		System.out.println(ans);
	}
}
