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)

/*--------------------------"SABUJ-JANA"------"JADAVPUR UNIVERSITY"--------*/
/*-------------------------------@greenindia-----------------------------------*/
//
//		  _____       _           _        _
//		 / ____|     | |         (_)      | |
//		| (___   __ _| |__  _   _ _       | | __ _ _ __   __ _
//		 \___ \ / _` | '_ \| | | | |  _   | |/ _` | '_ \ / _` |
//		 ____) | (_| | |_) | |_| | | | |__| | (_| | | | | (_| |
//		|_____/ \__,_|_.__/ \__,_| |  \____/ \__,_|_| |_|\__,_|
//		                        _/ |
//		                       |__/
/*---------------------- Magic. Do not touch.-----------------------------*/
/*------------------------------God is Great/\---------------------------------*/
#include <bits/stdc++.h>
using namespace std;
#define crap                     \
    ios::sync_with_stdio(false); \
    cin.tie(NULL);               \
    cout.tie(NULL)
//cout<<fixed<<showpoint<<setprecision(12)<<ans<<endl;
#define int long long int
#define double long double
#define PI acos(-1)
typedef vector<int> vi;
typedef vector<vector<int>> vvi;

void print1d(const vector<int>& vec) {
    for (auto val : vec) {
        cout << val << " ";
    }
    cout << endl;
}

void print2d(const vector<vector<int>>& vec) {
    for (auto row : vec) {
        for (auto val : row) {
            cout << val << " ";
        }
        cout << endl;
    }
}

signed main() {
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("error.txt", "w", stderr);
#endif
    crap;

    string str;
    cin >> str;

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

    return 0;
}