Score : $100$ points
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.
Input is given from Standard Input in the following format:
Print the string representing the type of the contest held this week.
They held an ABC last week, so they will hold an ARC this week.