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 Lua (Lua 5.3.5) (judge verdict: Accepted)

local s = io.read()

local function func(s)
	if s ~= "ARC" and s ~= "ABC" then
		return s
	end
	return ({ARC = "ABC",ABC = "ARC"})[s]
end


print(func(s))