#include<bits/stdc++.h>
#include "combo.h"
#define sz(s) (int(s.size()))
#define PB push_back
using namespace std;
// A B X Y
string guess_sequence(int n){
string ans;
if(press("AB"))
ans = press("A") ? "A" : "B";
else
ans = press("X") ? "X" : "Y";
vector<string> c;
for(string s : {"A", "B", "X", "Y"})
if(ans != s)
c.PB(s);
for(int i = 2; i < n; i++){
int coin = press(ans + c[0] + ans + c[1] + c[0] + ans + c[1] + c[1] + ans + c[1] + c[2]);
if(coin == sz(ans) + 1)
ans+= c[0];
else if(coin == sz(ans) + 2)
ans+= c[1];
else
ans+= c[2];
}
if(n > 1){
if(press(ans + c[0]) == n)
ans+= c[0];
else if(press(ans + c[1]) == n)
ans+= c[1];
else
ans+= c[2];
}
return ans;
}
