#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define REP(n) FOR(O, 1,(n))
#define f first
#define s second
#define pb push_back
typedef vector<int> vi;
typedef pair<int, int> pii;
std::string guess_sequence(int n) {
string buttons = "ABXY";
string ret = "";
FOR(i, 0, n-1) {
string ask = ret + buttons[0] + ret + buttons[1];
int coins = press(ask);
if (coins > i) {
ask = ret + buttons[0];
coins = press(ask);
if (coins > i)
ret += buttons[0];
else
ret += buttons[1];
} else {
ask = ret + buttons[2];
coins = press(ask);
if (coins > i)
ret += buttons[2];
else
ret += buttons[3];
}
}
return ret;
}
