import java.io.*;

public class Main {
    public static void main (String[] args) throws Exception {
        BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in));
        String S = reader.readLine();
        System.out.println ("ARC".equals (S) ? "ABC" : "ARC");
        return;
    }
} import java.io.*; io.* java public class Main {
    public static void main (String[] args) throws Exception {
        BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in));
        String S = reader.readLine();
        System.out.println ("ARC".equals (S) ? "ABC" : "ARC");
        return;
    }
} Main public static void main (String[] args) throws Exception {
        BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in));
        String S = reader.readLine();
        System.out.println ("ARC".equals (S) ? "ABC" : "ARC");
        return;
    } main {
        BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in));
        String S = reader.readLine();
        System.out.println ("ARC".equals (S) ? "ABC" : "ARC");
        return;
    } BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in)); reader new BufferedReader (new InputStreamReader (System.in)) String S = reader.readLine(); S reader.readLine() reader.readLine reader System.out.println ("ARC".equals (S) ? "ABC" : "ARC") System.out.println System.out System System.out "ARC".equals (S) ? "ABC" : "ARC" "ARC".equals (S) "ARC".equals "ARC" S "ABC" "ARC" return; String[] args args public class Main {
    public static void main (String[] args) throws Exception {
        BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in));
        String S = reader.readLine();
        System.out.println ("ARC".equals (S) ? "ABC" : "ARC");
        return;
    }
} public class Main {
    public static void main (String[] args) throws Exception {
        BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in));
        String S = reader.readLine();
        System.out.println ("ARC".equals (S) ? "ABC" : "ARC");
        return;
    }
} Main
import java.io.*;

public class Main {
    public static void main (String[] args) throws Exception {
        BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in));
        String S = reader.readLine();
        System.out.println ("ARC".equals (S) ? "ABC" : "ARC");
        return;
    }
}