#include "combo.h"
#include <vector>
using namespace std;
string guess_sequence(int N) {
string p = "AB";
int coins = press(p);
string start;
if (coins){
string q = "A";
coins = press(q);
if (coins){
start = "A";
} else {
start = "B";
}
} else {
string q = "X";
coins = press(q);
if (coins){
start = "X";
} else {
start = "Y";
}
}
vector<string> other;
if (start != "A"){
other.push_back("A");
}
if (start != "B"){
other.push_back("B");
}
if (start != "X"){
other.push_back("X");
}
if (start != "Y"){
other.push_back("Y");
}
string S = start;
for (int i = 1; i < N - 1; ++i) {
string query = S + other[1];
query += (S + other[2] + other[0]);
query += (S + other[2] + other[1]);
query += (S + other[2] + other[2]);
int res = press(query);
S += other[res - i];
}
int r1 = press(S + other[0]);
if (r1 == N){
return S + other[0];
}
int r2 = press(S + other[1]);
if (r2 == N){
return S + other[1];
}
return S + other[2];
}
