import java.io.*;
import java.util.*;
import java.lang.*;

public class Main {
	public static void main (String[] args) {
		Scanner sc=new Scanner(System.in);
		String str=sc.nextLine();
	    String	str1="ABC";
		if(str.equals(str1))
		System.out.println("ARC");
		else
		System.out.println("ABC");
	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz