#include "combo.h"
#include<bits/stdc++.h>
using namespace std;
string p,ans;
std::string guess_sequence(int N) {
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)ans+=p[2];
else if(ans.size()==t+1)ans+=p[0];
else if(ans.size()==t+2)ans+=p[1];
}
if(press(ans+p[0])==N)return ans+p[0];
else if(press(ans+p[1])==N)return ans+p[1];
else return ans+p[2];
}