#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
#define sz size()
string guess_sequence(int n) {
string ans="";
vector<char> v={'A','B','X','Y'};
int f=press("AB");
if(f==2)
ans+="A";
else if(f==1){
if(press("A")==1)
ans+="A";
else
ans+="B";
}
else{
if(press("X")==1)
ans+="X";
else
ans+="Y";
}
for(int i = 0; i < 4; i++){
if(v[i]==ans[0]){
v.erase(v.begin()+i);
break;
}
}
for(int i = 1; i < n-1; i++){
string q=ans+v[0]+v[0]+ans+v[0]+v[1]+ans+v[0]+v[2]+ans+v[1];
int x=press(q)-ans.sz;
if(x==2)
ans+=v[0];
else if(x==1)
ans+=v[1];
else
ans+=v[2];
}
if(n>1){
if(press(ans+v[0])==n)
ans+=v[0];
else if(press(ans+v[1])==n)
ans+=v[1];
else
ans+=v[2];
}
return ans;
}
