#include <iostream>
#include <algorithm>
#include <cmath>
#include <queue>
#include <utility>
#include <map>
#include <climits>
#include <vector>
#include <set>
#include <string>
#include <numeric>

#define FAST_IO ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr)
#define flood(arr, c, s) for (int i=0; i<s; i++) arr[i] = c
//#define int long long
using namespace std;
typedef vector<int> vi;
typedef pair<int, int> ii;
typedef vector<pair<int, int>> vii;
const int N = 1e5 + 2;
const int INF = 1e9 + 5;
const int MOD = 1e9 + 7;

int32_t main() {
    FAST_IO;
    string s;
    cin >> s;
    cout << (s == "ABC" ? "ARC" : "ABC");
    return 0;
}