import java.io.*;
import java.util.*;
import static java.lang.System.*;
import static java.lang.Math.*;

public class Main
{	
	public static void main(String []args)throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		boolean flag=false;
		String ans="";
		
		String S = br.readLine();
		
		if(S.charAt(1) == 'B')
			ans="ARC";
		else
			ans="ABC";
		
		
		out.println(ans);
		
	}
	
	
}

 import java.io.*; io.* java import java.util.*; util.* java import static java.lang.System.*; import static java.lang.System.*; import static java.lang.System.*; import static java.lang.Math.*; import static java.lang.Math.*; import static java.lang.Math.*; public class Main
{	
	public static void main(String []args)throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		boolean flag=false;
		String ans="";
		
		String S = br.readLine();
		
		if(S.charAt(1) == 'B')
			ans="ARC";
		else
			ans="ABC";
		
		
		out.println(ans);
		
	}
	
	
} Main public static void main(String []args)throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		boolean flag=false;
		String ans="";
		
		String S = br.readLine();
		
		if(S.charAt(1) == 'B')
			ans="ARC";
		else
			ans="ABC";
		
		
		out.println(ans);
		
	} main {
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		boolean flag=false;
		String ans="";
		
		String S = br.readLine();
		
		if(S.charAt(1) == 'B')
			ans="ARC";
		else
			ans="ABC";
		
		
		out.println(ans);
		
	} BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) boolean flag=false; flag false String ans=""; ans "" String S = br.readLine(); S br.readLine() br.readLine br 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="ABC" ans "ABC" out.println(ans) out.println out ans String []args args public class Main
{	
	public static void main(String []args)throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		boolean flag=false;
		String ans="";
		
		String S = br.readLine();
		
		if(S.charAt(1) == 'B')
			ans="ARC";
		else
			ans="ABC";
		
		
		out.println(ans);
		
	}
	
	
} public class Main
{	
	public static void main(String []args)throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		boolean flag=false;
		String ans="";
		
		String S = br.readLine();
		
		if(S.charAt(1) == 'B')
			ans="ARC";
		else
			ans="ABC";
		
		
		out.println(ans);
		
	}
	
	
} Main
import java.io.*;
import java.util.*;
import static java.lang.System.*;
import static java.lang.Math.*;

public class Main
{	
	public static void main(String []args)throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		boolean flag=false;
		String ans="";
		
		String S = br.readLine();
		
		if(S.charAt(1) == 'B')
			ans="ARC";
		else
			ans="ABC";
		
		
		out.println(ans);
		
	}
	
	
}


