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)

var debug = false;

function Main(input) {
    console.log(input.startsWith('ARC') ? 'ABC' : 'ARC');
}




//*この行以降は編集しないでください（標準入出力から一度に読み込み、Mainを呼び出します）
if (debug) {
    Main(require("fs").readFileSync("./input", "utf8")); 
} else { 
    Main(require("fs").readFileSync("/dev/stdin", "utf8"));
}