#include <bits/stdc++.h>

using namespace std;
#ifdef ONLINE_JUDGE
#define cerr if(false)cerr
#endif
//#define int long long
#define ld1 long double
#define watch(x) cerr << (#x) << " is " << (x) << endl
#define faster ios_base::sync_with_stdio(false),cin.tie(NULL),cout.tie(NULL),cout<<setprecision(14);
#define cint int t;cin>>t;while(t--)
#define vint vector<int>
#define all(v) (v).begin(), (v).end()
#define pii pair<int,int>
#define pb push_back
#define N 50011
#define mm0(X) memset((X), 0, sizeof((X)))
#define mm1(X) memset((X), -1, sizeof((X)))
#define MAXN (int)1e6 + 11
#define INF (int)1e9
#define READ(f) freopen(f, "r", stdin)
#define WRITE(f) freopen(f, "w", stdout)
#define endl '\n'

const int mod=1000000007;
int powmod(int a,int b) {int res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
int gcd(int a,int b){return b?gcd(b,a%b):a;}

void solve(){
    string s;
    cin>>s;
    if(s=="ABC") cout<<"ARC"<<endl;
    else cout<<"ABC"<<endl;
}

int32_t main() {
    faster;

#ifndef ONLINE_JUDGE
    READ("inp.txt");
    WRITE("out.txt");
    double beg=clock();
#endif

    int t=1;
//    cin>>t;

    while(t--){
        solve();
    }

#ifndef ONLINE_JUDGE
    double end=clock();
    cerr<<"*** Total time = "<<(end-beg)/CLOCKS_PER_SEC;
#endif
}
