#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
// int press(string p)
int n,cur;
string ans, x;
map<char,int> m;
char v[] = {'A','B','X','Y'};
// AA AB AC BA BB BC CA CB CC
//
int delta(string s)
{
return ( press(s) - cur );
}
void BuildMap()
{
m.insert({'A',0});
m.insert({'B',1});
m.insert({'X',2});
m.insert({'Y',3});
return;
}
void FirstLetter()
{
if( delta( "AB" ) )
{
if( delta( "A" ) ) ans.push_back('A');
else ans.push_back('B');
}
else
{
if( delta( "X" ) ) ans.push_back('X');
else ans.push_back('Y');
}
cur++;
return;
}
void AddSingle()
{
if( delta( ans + x[0] ) )
{
ans.push_back(x[0]);
}
else
{
if( delta( ans + x[1]) ) ans.push_back(x[1]);
else ans.push_back(x[2]);
}
cur++;
return;
}
string guess_sequence(int N)
{
FirstLetter();
n = N;
for(int i=0;i<4;i++)
{
if(v[i] == ans[0]) continue;
x.push_back(v[i]);
}
while(cur < n) AddSingle();
return ans;
}
