# include <iostream>
# include <vector>
# include <algorithm>
using namespace std;
# include "combo.h"
//# include "grader.cpp"
string guess_sequence(int N)
{
vector<char> letters={'A','B','X','Y'};
string s;
int l=0,r=letters.size()-1,lett=0;
while(l<r)
{
int mid=(l+r)/2;
string guess;
for(int i=l;i<=mid;i++) guess.push_back(letters[i]);
if(press(guess))
{
r=mid;
lett=mid;
}
else
{
l=mid+1;
lett=mid+1;
}
}
s.push_back(letters[lett]);
letters.erase(letters.begin()+lett);
if(N==1) return s;
//cout<<"->"<<s<<endl;
for(int i=2;i<N;i++)
{
string guess=s+letters[0]+s+letters[1]+letters[0]+s+letters[1]+letters[1]+s+letters[1]+letters[2];
int resp=press(guess);
if(resp==i) s.push_back(letters[0]);
else if(resp==i+1) s.push_back(letters[1]);
else s.push_back(letters[2]);
}
string guess=s+letters[0];
if(press(guess)==N) s.push_back(letters[0]);
else
{
guess=s+letters[1];
if(press(guess)==N) s.push_back(letters[1]);
else s.push_back(letters[2]);
}
return s;
}
/*
ABXYY
*/
/*
YXX
*/
