#include<iostream>
#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<vector>
#include<queue>
#include<map>
#include<set>
#include<iomanip>
#include<cmath>

#define REP(i,n) for (int i = 0; (i) < (n); ++ (i))
#define FOR(i,n) for (int i = 1; (i) <= (n); ++ (i))
#define dump(x)  cout << #x << " = " << (x) << endl;
#define pb push_back
#define int long long

const int INF = 1e18;
const int MOD = 1e9+7;
//const lint LINF = 1e18;
const double eps = 0.000000001;//もとの値の10^(-16)まで

using namespace std;

//typedef pair<int, int> P;
//priority_queue< P, vector<P>, greater<P> > q;//ダイクストラの時、greaterで小さい順
//cout << fixed << setprecision(10) << ans << endl;
//int gcd(int a,int b){return b?gcd(b,a%b):a;}

signed main(){
    string s;
    cin >> s;
    if(s== "ABC"){
        cout << "ARC" << endl;
    }
    else{
        cout << "ABC" << endl;
    }
    return 0;
}