#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
string ret;
vector<string> f = { "A", "B", "X", "Y" };
string guess_sequence(int N) {
if(press("AB")) {
if(press("A")) ret = "A";
else ret = "B";
} else {
if(press("X")) ret = "X";
else ret = "Y";
}
for(int i = 0; i < 4; i++) if(f[i] == ret) f.erase(f.begin() + i);
for(int i = 1; i < N-1; i++) {
string t = ret+f[0]+f[0]+ret+f[0]+f[1]+ret+f[0]+f[2]+ret+f[1];
int r = press(t);
if(r == i+2) ret += f[0];
else if(r == i+1) ret += f[1];
else ret += f[2];
}
if(N > 1) {
if(press(ret+f[0]) == N) ret += f[0];
else if(press(ret+f[1]) == N) ret += f[1];
else ret += f[2];
}
return ret;
}
