题目描述
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-----
ABC
-----Sample Output-----
ARC
They held an ABC last week, so they will hold an ARC this week.
输入格式
见题面
输出格式
见题面
样例输入
ABC
样例输出
ARC