#include <bits/stdc++.h>
using namespace std;

#define INF_LL (int64)1e18
#define INF (int32)1e9
#define REP(i, n) for(int64 i = 0;i < (n);i++)
#define FOR(i, a, b) for(int64 i = (a);i < (b);i++)
#define all(x) x.begin(),x.end()
#define fs first
#define sc second

using int32 = int_fast32_t;
using uint32 = uint_fast32_t;
using int64 = int_fast64_t;
using uint64 = uint_fast64_t;
using PII = pair<int32, int32>;
using PLL = pair<int64, int64>;

const double eps = 1e-10;

template<typename A, typename B>inline void chmin(A &a, B b){if(a > b) a = b;}
template<typename A, typename B>inline void chmax(A &a, B b){if(a < b) a = b;}

template<typename T>
vector<T> make_v(size_t a){return vector<T>(a);}

template<typename T,typename... Ts>
auto make_v(size_t a,Ts... ts){
	return vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));
}

template<typename T,typename U,typename... V>
typename enable_if<is_same<T, U>::value!=0>::type
fill_v(U &u,const V... v){u=U(v...);}

template<typename T,typename U,typename... V>
typename enable_if<is_same<T, U>::value==0>::type
fill_v(U &u,const V... v){
	for(auto &e:u) fill_v<T>(e,v...);
}

class UnionFind{
private:
  ::std::vector<int_fast32_t> par;
  size_t n;

public:
  UnionFind(){}
  UnionFind(size_t n):n(n){
    par.resize(n, -1);
  }

  uint_fast32_t find(uint_fast32_t x){
    return par[x] < 0 ? x : par[x] = find(par[x]);
  }

  size_t size(uint_fast32_t x){
    return -par[find(x)];
  }

  bool unite(uint_fast32_t x, uint_fast32_t y){
    x = find(x);
    y = find(y);
    if(x == y) return false;
    if(size(x) < size(y)) std::swap(x, y);
    par[x] += par[y];
    par[y] = x;
    return true;
  }

  bool same(uint_fast32_t x, uint_fast32_t y){
    return find(x) == find(y);
  }
};

template<class ValueMonoid, template<class...> class Container=::std::vector>
class SegTree{
public:
  using value_structure = ValueMonoid;
  using value_type = typename value_structure::value_type;
  using const_reference = const value_type &;
  using container_type = Container<value_type>;
  using size_type = typename container_type::size_type;

private:
  ::std::vector<value_type> tree;
  size_type size_;

  static size_type getsize(const size_type x){
    size_type ret = 1;
    while(ret < x)
      ret <<= 1;
    return ret;
  }

  inline value_type calc(const value_type a, const value_type b){
    return value_structure::operation(a, b);
  }

  inline void calc_node(const size_type index){
    if(tree.size() <= (index << 1 | 1)) return;
    tree[index] = value_structure::operation(tree[index<<1], tree[index<<1 | 1]);
  }
public:
  SegTree() : size_(0), tree(){}
  SegTree(const size_type size)
    : size_(size), tree(size << 1, value_structure::identity()){}
  template<class InputIterator>
  SegTree(InputIterator first, InputIterator last)
    : size_(::std::distance(first, last)){
    tree = container_type(size_, value_structure::identity());
    tree.insert(tree.end(), first, last);
    for(size_type i = size_;i > 0;i--){
      calc_node(i);
    }
  }

  size_type size() const { return size_; }
  const_reference operator[](const size_type k) const {
    assert(k < size_);
    return tree[k+size_];
  }

  value_type query(size_type l, size_type r){
    assert(l <= r);
    assert(0 <= l && l < size_);
    assert(0 <= r && r <= size_);
    value_type retl = value_structure::identity(), retr = value_structure::identity();
    for(l += size_, r += size_; l < r ; l >>= 1, r >>= 1){
      if(l&1) retl = calc(retl, tree[l++]);
      if(r&1) retr = calc(tree[--r], retr);
    }
    return calc(retl, retr);
  }

  template<class F>
  void update(size_type index, const F& f){
    assert(0 <= index && index < size());
    index += size_;
    tree[index] = f(::std::move(tree[index]));
    while(index >>= 1)
      calc_node(index);
  }

  /*
  template<class F>
  size_type search(const F& f) const { // [0, result) is True and [0, result-1) is not.
    if(f(value_structure::identity()))
      return 0;
    if(!f(tree[1]))
      return size_+1;
    value_type acc = value_structure::identity();
    size_type i = 1;
    while(i <
  }
  */
};

template<class ValueMonoid, class OperatorMonoid, class Modifier,
  template<class...> class Container=::std::vector>
class LazySegTree{
public:
  using value_structure = ValueMonoid;
  using value_type = typename value_structure::value_type;
  using operator_structure = OperatorMonoid;
  using operator_type = typename operator_structure::value_type;
  using modifier = Modifier;
  using const_reference = const value_type &;
  using container_value_type = Container<value_type>;
  using container_operator_type = Container<operator_type>;
  using size_type = typename container_value_type::size_type;

private:
  container_value_type tree;
  container_operator_type lazy;
  size_type size_, height;

  static size_type getsize(const size_type x){
    size_type ret = 1;
    while(ret < x)
      ret <<= 1;
    return ret;
  }

  static size_type getheight(const size_type x){
    size_type ret = 0;
    while((static_cast<size_type>(1) << ret) < x){
      ret++;
    }
    return ret;
  }

  inline static value_type calc(const value_type a, const value_type b){
    return value_structure::operation(a, b);
  }

  inline static void apply(operator_type &data, const operator_type a){
    data = operator_structure::operation(data, a);
  }

  inline static value_type reflect(const value_type v, const operator_type o){
    return modifier::operation(v, o);
  }

  void push(const size_type index){
    tree[index] = reflect(tree[index], lazy[index]);
    apply(lazy[index << 1], lazy[index]);
    apply(lazy[index << 1 | 1], lazy[index]);
    lazy[index] = operator_structure::identity();
  }

  void calc_node(const size_type index){
    if(tree.size() <= (index << 1 | 1)) return;
    assert(0 < index);
    tree[index] = calc(reflect(tree[index << 1],  lazy[index << 1]),
                       reflect(tree[index << 1 | 1], lazy[index << 1 | 1]));
  }

  void build(size_type index){
    while(index >>= 1){
      calc_node(index);
    }
  }

  void propagate(const size_type index){
    for(size_type shift = height; shift ; --shift){
      push(index >> shift);
    }
  }

  void rebuild(){
    for(size_type i = size_-1;i > 0;--i){
      calc_node(i);
    }
  }
public:
  LazySegTree() : size_(0), height(0), tree(), lazy(){}
  LazySegTree(const size_type size)
    : size_(size), height(getheight(size)),
      tree(size << 1, value_structure::initializer()),
      lazy(size << 1, operator_structure::identity()){
    rebuild();
  }
  template<class InputIterator>
  LazySegTree(InputIterator first, InputIterator last)
    : size_(::std::distance(first, last)){
    height = getheight(size_);
    tree = container_value_type(size_, value_structure::identity());
    lazy = container_operator_type(size_ << 1, operator_structure::identity());
    tree.insert(tree.end(), first, last);
    rebuild();
  }

  size_type size() const { return size_; }
  const_reference operator[](const size_type k){
    assert(k < size_);
    propagate(k+size_);
    tree[k+size_] = reflect(tree[k+size_], lazy[k+size_]);
    lazy[k+size_] = operator_structure::identity();
    return tree[k+size_];
  }

  value_type query(size_type l, size_type r){
    assert(l <= r);
    assert(0 <= l && l < size_);
    assert(0 <= r && r <= size_);
    value_type retl = value_structure::identity(),
      retr = value_structure::identity();
    l += size_;
    r += size_;
    propagate(l);
    propagate(r-1);
    build(l);
    build(r-1);
    for(; l < r ; l >>= 1, r >>= 1){
      if(l&1){
        retl = calc(retl, reflect(tree[l], lazy[l]));
        l++;
      }
      if(r&1){
        r--;
        retr = calc(reflect(tree[r], lazy[r]), retr);
      }
    }
    return calc(retl, retr);
  }

  void update(size_type l, size_type r, const operator_type& data){
    assert(l <= r);
    assert(0 <= l && l < size_);
    assert(0 <= r && r <= size_);
    l += size_;
    r += size_;
    propagate(l);
    propagate(r - 1);
    for(size_type l_ = l, r_ = r; l_ < r_ ; l_ >>= 1, r_ >>= 1){
      if(l_ & 1) apply(lazy[l_++], data);
      if(r_ & 1) apply(lazy[--r_], data);
    }
    build(l);
    build(r - 1);
  }

  template<class F>
  void update(size_type index, const F& f){
    assert(0 <= index && index < size());
    index += size_;
    propagate(index);
    tree[index] = f(::std::move(tree[index]));
    lazy[index] = operator_structure::identity();
    build(index);
  }

  /*
  template<class F>
  size_type search(const F& f) const { // [0, result) is True and [0, result-1) is not.
    if(f(value_structure::identity()))
      return 0;
    if(!f(tree[1]))
      return size_+1;
    value_type acc = value_structure::identity();
    size_type i = 1;
    while(i <
  }
  */
};

class v_monoid {
public:
  using value_type = int64;
  static value_type identity() { return 0; }
  static value_type initializer() { return 0; }
  static value_type operation(const value_type& a, const value_type& b) {
    return a + b;
  }
};

class o_monoid {
public:
  using value_type = int64;
  static value_type identity() { return 0; }
  static value_type operation(const value_type& a, const value_type& b) {
    return a + b;
  }
};

class modifier {
public:
  static int64 operation(const int64& a, const int64& b) {
    return a + b;
  }
};

int64 dy[4] = {-1, 1, 0, 0};
int64 dx[4] = {0, 0, -1, 1};

int64 N, M;
vector<PLL> G[112345];
using T = tuple<int64, int64, int64, int64>;
vector<T> e;

int64 par[20][112345] = {};
int64 cost[20][112345] = {};
vector<int64> dep;

void dfs(int64 v, int64 p, int64 d=0) {
  dep[v] = d;
  for (auto& [c, u]: G[v]) {
    if (u == p) continue;
    par[0][u] = v;
    cost[0][u] = c;
    dfs(u, v, d+1);
  }
}

int64 lca(int64 u, int64 v) {
  if (dep[u] < dep[v]) swap(u, v);
  int64 ret = 0;
  REP(i, 20) {
    if ((dep[u] - dep[v]) >> i & 1) {
      chmax(ret, cost[i][u]);
      u = par[i][u];
    }
  }
  if (u == v) return ret;
  for (int64 i = 19; i >= 0; i--) {
    if (par[i][u] != par[i][v]) {
      chmax(ret, max(cost[i][u], cost[i][v]));
      u = par[i][u];
      v = par[i][v];
    }
  }
  if (u != v) {
    chmax(ret, max(cost[0][u], cost[0][v]));
  }
  return ret;
}

int main(void) {
  cin.tie(0);
  ios::sync_with_stdio(false);
  string S;
  cin >> S;
  cout << (S == "ABC" ? "ARC" : "ABC") << endl;
}



Measured memory_bytes: 6292