#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
const int MAX = 1e9 + 7;
//vector<int> dp(MAX, MAX);
string guess_sequence(int N) {
string firstchar;
if (press("AB") != 0) {
if (press("A") == 1) {firstchar = "A";}
else {firstchar = "B";}
}
else {
if (press("X") == 1) {firstchar = "X";}
else {firstchar = "Y";}
}
if (N == 1) {
return firstchar;
}
vector<string> possible = {"A", "B", "X", "Y"};
possible.erase(remove(possible.begin(), possible.end(), firstchar), possible.end());
string final = firstchar;
for (int i = 0; i < N - 2; i++) {
string sending = "";
for (int j = 0; j < 3; j++) {
sending += final + possible[0] + possible[j]; // will give i + 3
}
sending += final + possible[1]; // will give i + 2
int resul = press(sending);
if (resul == i+3) {
final += possible[0];
}
else if (resul == i+2) {
final += possible[1];
}
else {
final += possible[2];
}
}
if (press(final + possible[0] + final + possible[1]) == N) {
if (press(final + possible[0]) == N) {return final + possible[0];}
else {return final + possible[1];}
}
else {return final + possible[2];}
}
