#include <iostream>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <vector>
#include <iomanip>
#include <queue>
#include <stack>
#include <deque>
#include <algorithm>

using namespace std;

#define ll long long
#define endl '\n'
#define mod 1000000007
#define mx 2000005
#define pb push_back
#define fr(a,b) for(int i = a; i < b;i++)

bool p[mx + 1];
ll fact[mx];
vector<int> prime;

void seieve(){
	for (int i = 2; i * i <= mx; i++){
		if (!p[i])
			for (int j = i * i; j <= mx; j += i)
				p[j] = 1;
	}
	for (int i = 2; i <= mx; i++)
		if (!p[i])
			prime.pb(i);
}

bool isprime(ll n){
	if (n <= 1)
		return false;
	for (ll i = 2; i * i <= n; i++)
		if (n % i == 0)
			return false;
	return true;
}

void factorial(){
	fact[0] = 1;
	for (int i = 1; i < mx; i++){
		fact[i] = fact[i - 1] * i;
		fact[i] %= mod;
	}
}

ll modInverse(ll a){
	ll m0 = mod;
	ll y = 0, x = 1;
	if (m0 == 1)
		return 0;

	while (a > 1){
		ll q = a / m0;
		int t = m0;
		m0 = a % m0, a = t;
		t = y;
		y = x - q * y;
		x = t;
	}
	if (x < 0)
		x += mod;
	return x;
}

ll power(ll x, ll y, ll p){
	ll res = 1;
	x = x % p;
	if (x == 0)
		return 0;
	while (y > 0){
		if (y & 1)
			res = (res * x) % p;
		y = y >> 1;
		x = (x * x) % p;
	}
	return res;
}

ll nCr(int n, int r){
	return ((fact[n] * modInverse(fact[n - r])) % mod * modInverse(fact[r])) % mod;
}

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

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	int t = 1;
	while (t--){
		solve();
	}
	return 0;
}