#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
string chars = "ABXY";
string guess_sequence(int N) {
string S = "";
for(int i = 0; i < 4; i++){
int res = press(chars.substr(i, 1));
if(res) S+=chars[i];
}
for(int i = 0; i < N-1; i++){
vector<string> opts;
for(int j = 0; j < 4; j++){
if(chars[j]==S[0]) continue;
opts.push_back(S+chars[j]);
}
if(press(opts[0]+opts[1])==2*(int)S.size()){
S=opts[2];
}else{
if(press(opts[0]+opts[2])==2*(int)S.size()){
S=opts[1];
}else S=opts[0];
}
}
return S;
}
