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 JavaScript (Node.js 12.16.1) (judge verdict: Accepted)

function main(arg) {
    let data = arg.trim().split("\n")[0]
    let list = {
        'ABC': 'ARC',
        'ARC': 'ABC'
    }
    console.log(list[data])
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));