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 C++ (Clang 10.0.0) (judge verdict: Accepted)

#include <algorithm>
#include <array>
#include <cmath>
#include <deque>
#include <iostream>
#include <set>
#include <string>

using namespace std;

int main() {
  string str;

  cin >> str;

  if (str == "ABC") {
    cout << "ARC" << endl;
  } else {
    cout << "ABC" << endl;
  }

  return 0;
}