#include "combo.h"
#include "bits/stdc++.h"
using namespace std;
vector < char > v = {'A', 'B', 'X', 'Y'};
string guess_sequence(int n) {
string s = "";
for(int i = 0; i < v.size() - 1; i++){
if(press(s + v[i])){
s += v[i];
break;
}
}
if(!s.size())s += v.back();
vector < char > vv;
for(char c : v){
if(c != s[0])
vv.push_back(c);
}
if(n == 1){
return s;
}
v = vv;
while(s.size() <= n - 2){
string cur = "";
cur += (s + v[0]);
cur += (s + v[1] + v[0]);
cur += (s + v[1] + v[1]);
cur += (s + v[1] + v[2]);
int g = press(cur);
if(g == s.size()){
s += v[2];
}
else if(g == s.size() + 1){
s += v[0];
}
else {
s += v[1];
}
}
for(int i = 0; i < v.size() - 1; i++){
if(press(s + v[i])){
s += v[i];
return s;
}
}
s += v.back();
return s;
}
