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)

///******* In the name of Allah *******///

#include <bits/stdc++.h>
using namespace std;

//long int ar[90013],br[100013];
//long int gcd(long int a, long int b)
//{
//    if(b==0)
//        return a;
//    return gcd(b,a%b);
//}
//long int sieve(long long int a)
//{
//    //long long int i,j,k = 0;
//    memset(ar,0,sizeof(ar));
//    ar[1] = 1;
//    for(i=2; i<=90013; i++)
//    {
//        if(ar[i]==0)
//        {
//            k++;
//            br[k] = i;
//            for(j=i+i; j<=90013; j+=i)
//            {
//                ar[j] = 1;
//            }
//        }
//    }
//    return br[a];
//}

void Ok()
{
    long int a[77],b,c,d,h,t,i,j,k,l,m,n;
    long int ans_1,ans_2,ans_3,ans_4,cnt = 0,Max,Min,flag,temp,sum_1,sum_2;
    double aa,bb,cc,dd,ee,ff,gg;
    char aaa[10013],bbb,ccc,ddd;
    string spc,in;

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

    return;
}

int main()
{
    Ok();

    return 0;
}