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;
using ll = long long;
using vec = vector<ll>;
using mat = vector<vec>;
using vec_b = vector<bool>;
using vec_str = vector<string>;
using graph = mat;
using edge = pair<ll,ll>;
using wgraph = vector<vector<edge>>;

#define INF (1LL << 60)
#define MOD 1000000007

#define REP(i,m,n) for(ll (i)=(m),i##_len=(n);(i)<(i##_len);++(i))
#define FORR(i,v) for(auto (i):v)
#define ALL(x) (x).begin(), (x).end()
#define _PR(x) cout << (x) << endl
#define _PS(x) cout << (x) << " "
#define SZ(x) ((ll)(x).size())
#define MAX(a,b) (((a)>(b))?(a):(b))
#define MIN(a,b) (((a)<(b))?(a):(b))
#define pb push_back


int main()
{
    string S;
    cin >> S;
    if(S == "ABC") _PR("ARC");
    else _PR("ABC");


    return 0;
}

/*



*/