#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using pii = pair<int, int>;


int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);


    string s;
    cin >> s;

    if (s == "ABC") {
        cout << "ARC" << endl;
    } else {
        cout << "ABC" << endl;
    }


    return 0;
}

