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)

        //Bismillah hirrahmanir Rahim
        #include<bits/stdc++.h>
        #define ll long long
        #define pb push_back
        #define dbug printf("I am here\n");
        #define Fast ios_base::sync_with_stdio(false); cin.tie(0);
        const int m = 10e6;
        using namespace std;

        int main(){
         long long int a,b,tst,k;
         string s;
         cin>>s;
        if(s[1]=='R')cout<<"ABC"<<endl;
        else cout<<"ARC"<<endl;
           return 0;

        }