#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
string guess_sequence(int N) {
string S = "";
int cost;
// find the first character (0)
cost = press("AB");
if (cost >= 1) {
cost = press("A");
if (cost == 1) S = "A";
else S = "B";
}
else {
cost = press("X");
if (cost == 1) S = "X";
else S = "Y";
}
if (N == 1) return S;
// setup
string T = "ABXY";
vector<char> chr;
for (char c : T) if (c != S[0]) chr.push_back(c);
// find character from 1 -> N - 2
for (int i = 1; i < N - 1; i++) {
string NS = S + chr[0] + chr[0] + S + chr[0] + chr[1] + S + chr[0] + chr[2] + S + chr[1];
cost = press(NS);
if (cost == i) S = S + chr[2];
if (cost == i + 1) S = S + chr[1];
if (cost == i + 2) S= S + chr[0];
}
// find character N - 1
if (press(S + chr[0]) == N) S = S + chr[0];
else if (press(S + chr[1]) == N) S = S + chr[1];
else S = S + chr[2];
return S;
}
