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++ (GCC 9.2.1) (judge verdict: Accepted)

#include <bits/stdc++.h>

using namespace std;

using lint = long long;

#define MOD_NUMBER 1000000007

template <class T> void vector_print(vector<T> vec) {
  for (unsigned int i = 0; i < vec.size(); i++) {
    cout << vec.at(i);
    if (i < vec.size()-1) {
      cout << " ";
    } else if (i == vec.size()-1) {
      cout << endl;
    }
  }
}

int main() {
  string S;
  cin >> S;
  if (S == "ABC") {
    cout << "ARC" << endl;
  } else if (S == "ARC") {
    cout << "ABC" << endl;
  }
  return 0;
}