#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
std::string guess_sequence(int N) {
string ans,p;
if(press("AB")){
if(press("A"))ans="A",p="BXY";
else ans="B",p="AXY";
}
else{
if(press("X"))ans="X",p="ABY";
else ans="Y",p="ABX";
}
if(N==1)return ans;
while(ans.size() <N-1){
int t = press(ans+p[0] +ans+p[1]+p[0] +ans+p[1]+p[1] +ans+p[1]+p[2]);
if(ans.size() == t-1)ans+=p[0];
else if(ans.size() == t-2)ans+=p[1];
else ans+=p[2];
}
if(ans.size() != press(ans+p[0]))ans+=p[0];
else if(ans.size() != press(ans+p[1]))ans+=p[1];
else ans+=p[2];
return ans;
}