Problem:
Score : 100 points

Problem Statement

AtCoder Inc. holds a contest every Saturday.

There are two types of contests called ABC and ARC, and just one of them is held at a time.

The company holds these two types of contests alternately: an ARC follows an ABC and vice versa.

Given a string S representing the type of the contest held last week, print the string representing the type of the contest held this week.

Constraints

S is ABC or ARC.

Input

Input is given from Standard Input in the following format:

S

Output

Print the string representing the type of the contest held this week.

Sample Input 1

ABC

Sample Output 1

ARC

They held an ABC last week, so they will hold an ARC this week.

Solution in Java (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.Scanner;

/**
 * @author hellb
 *
 */
public class Main {

	private static String ARC = "ARC";

	private static String ABC = "ABC";

	/**
	 * @param args
	 */
	public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);
        String sNum1 = scan.next();
        String sResult;
        scan.close();

        if (ARC.equals(sNum1)) {
        	sResult = ABC;
        } else {
        	sResult = ARC;
        }
        System.out.print(sResult);
	}
}