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;
#define rep(i,n) for(ll i=0; i<n; i++)
#define eb(t) emplace_back(t)
typedef long long ll;
typedef long long unsigned int llu;
ll INF = 1000000009;
ll MOD = 1000000007;



void solve(){

    string s;
    cin >> s;
    if(s=="ABC") cout << "ARC" << endl;
    else cout << "ABC" << endl;


}

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  solve();
  return 0;
}