import std;
enum inf(T)()if(__traits(isArithmetic,T)){return T.max/4;}
T scan(T=long)(){return readln.chomp.to!T;}
void scan(T...)(ref T args){auto input=readln.chomp.split;foreach(i,t;T)args[i]=input[i].to!t;}T[] scanarr(T=long)(){return readln.chomp.split.to!(T[]);}
alias Queue=DList;auto enq(T)(ref Queue!T q,T e){q.insertBack(e);}T deq(T)(ref Queue!T q){T e=q.front;q.removeFront;return e;}
alias Stack=SList;auto push(T)(ref Stack!T s,T e){s.insert(e);}T pop(T)(ref Stack!T s){T e=s.front;s.removeFront;return e;}
struct UnionFind(T){T[T]u;ulong[T] rank;@property{bool inc(T e){return e in u;}auto size(){return u.keys.length;}auto dup(){T[] child=u.keys;T[] parent=u.values;auto res=UnionFind!T(child);child.each!(e=>res.add(e));size.iota.each!(i=>res.unite(child[i],parent[i]));return res;}}this(T e){e.add;}this(T[] es){es.each!(e=>e.add);}auto add(T a,T b=a){assert(b.inc);u[a]=a;rank[a];if(a!=b)unite(a,b);}auto find(T e){if(u[e]==e)return e;return u[e]=find(u[e]);}auto same(T a,T b){return a.find==b.find;}auto unite(T a,T b){a=a.find;b=b.find;if(a==b)return;if(rank[a]<rank[b])u[a]=b;else{u[b]=a;if(rank[a]==rank[b])rank[a]++;}}}
struct PriorityQueue(T,alias less="a<b"){BinaryHeap!(T[],less) heap;@property{bool empty(){return heap.empty;}auto length(){return heap.length;}auto dup(){return PriorityQueue!(T,less)(array);}T[] array(){T[] res;auto tp=heap.dup;foreach(i;0..length){res~=tp.front;tp.removeFront;}return res;}void push(T e){heap.insert(e);}void push(T[] es){es.each!(e=>heap.insert(e));}}T look(){return heap.front;}T pop(){T tp=look;heap.removeFront;return tp;}this(T e){ heap=heapify!(less,T[])([e]);}   this(T[] e){ heap=heapify!(less,T[])(e);}}
//END OF TEMPLATE

void main(){
    auto c=scan!string;
    (c=="ABC"?"ARC":"ABC").writeln;
}
