#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
string guess_sequence(int N) {
string p ="",S="";
vector<char> lc={'A','B','X','Y'};
int bf=0;
while(S.size()<N){
p+=S+lc[lc.size()-1]+S+lc[lc.size()-2];
int coins = press(p);
if(coins>bf){
bf=coins;
p=S+lc[lc.size()-1];
coins=press(p);
if(coins==bf){
S+=lc[lc.size()-1];
}else{
S+=lc[lc.size()-2];
}
}else{
p=S+lc[lc.size()-3];
coins=press(p);
if(coins>bf){
bf=coins;
S+=lc[lc.size()-3];
}else{
bf++;
S+=lc[lc.size()-4];
}
}
}
return S;
}
