#include "bits/stdc++.h"
#include "combo.h"
//#define int long long
#define all(v) v.begin() , v.end()
#define sz(a) (int)a.size()
using namespace std;
vector<char> v;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
int ask(string s,int ekle){
s.push_back(v[ekle]);
return press(s);
}
string guess_sequence(int n){
string res="";
if(n==1){
if(press("A")==1) return "A";
if(press("B")==1) return "B";
if(press("Y")==1) return "Y";
return "X";
}
if(press("AB")>=1){
if(press("A")==1) res.push_back('A');
else res.push_back('B');
}
else{
if(press("X")==1) res.push_back('X');
else res.push_back('Y');
}
if(res!="A") v.push_back('A');
if(res!="B") v.push_back('B');
if(res!="X") v.push_back('X');
if(res!="Y") v.push_back('Y');
for(int i=1;i<n;i++){
if(i==n-1){
bool ok=0;
shuffle(all(v),rng);
for(int j=0;j<2;j++){
if(ask(res,j)==i+1){
res.push_back(v[j]);
ok=1;
break;
}
}
if(!ok) res.push_back(v.back());
}
else{
string Query="";
for(int i=0;i<3;i++){
Query+=res;
Query.push_back(v[0]);
Query.push_back(v[i]);
}
Query+=res;
Query.push_back(v[1]);
int hm = press(Query);
if(hm==i) res.push_back(v[2]);
else if(hm==i+1) res.push_back(v[1]);
else res.push_back(v[0]);
}
}
return res;
}
/*void _(){
}
int32_t main(){
cin.tie(0); ios::sync_with_stdio(0);
int tc=1;//cin >> tc;
while(tc--) _();
return 0;
}*/
