#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
string guess_sequence(int N) {
char ch[4] = {'A', 'B', 'X', 'Y'};
string ret = "";
string ask = "AB";
int len = press(ask);
if (len > 0) {
len = press("A");
if (len == 1) {
ret = "A";
}
else {
ret = "B";
}
}
else {
len = press("X");
if (len == 1) {
ret = "X";
}
else {
ret = "Y";
}
}
if (N == 1) {
return ret;
}
vector <char> options;
for (int i = 0; i < 4; i++) {
if (ch[i] != ret[0]) {
options.push_back(ch[i]);
}
}
for (int i = 2; i + 1 <= N; i++) {
ask = ret + options[0] + options[0] + ret + options[0] + options[1] + ret + options[0] + options[2] + ret + options[1];
len = press(ask);
if (len == (int) ret.size() + 2) {
ret += options[0];
}
else if (len == (int) ret.size() + 1) {
ret += options[1];
}
else {
ret += options[2];
}
}
ask = ret + options[0];
len = press(ask);
if (len == N) {
ret += options[0];
}
else {
ask = ret + options[1];
len = press(ask);
if (len == N) {
ret += options[1];
}
else {
ret += options[2];
}
}
return ret;
}
