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;
 
int main(){
	ios_base::sync_with_stdio(false); 
    cin.tie(NULL); 
#ifndef ONLINE_JUDGE 
    freopen("input.txt", "r", stdin); 
    freopen("output.txt", "w", stdout); 
#endif
  string s;
    cin>> s;
  if (s=="ABC"){
  cout<<"ARC";
  }
  else{
  cout<<"ABC";
  }
	return 0;
}