#define USE_MATH_DEFINES 1
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define MOD 998244353ll
#define INF 1000000000000000000ll
#define EPS 1e-9

#define getchar_unlocked _getchar_nolock
#define putchar_unlocked _putchar_nolock

typedef long long         ll;
typedef long double       ld;
typedef pair <ll,ll>      pl;
typedef tuple <ll,ll,ll>  tl;

string S;


int main() {

	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
	cin >> S;
	
	if (S == "ABC") cout << "ARC";
	else cout << "ABC";
	
    return 0;
}
