#include "combo.h"
#include <bits/stdc++.h>
#define ii pair<int, int>
#define fi first
#define se second
#define inf 0x3f3f3f3f3f3f3f3f
using namespace std;
using ll = long long;
const ll mod=1e9+7;
string guess_sequence(int n)
{
string res="";
if(press("AB"))
{
if(press("A")) res="A";
else res="B";
}
else
{
if(press("X")) res="X";
else res="Y";
}
string f="ABXY";
f.erase(f.begin()+f.find(res));
if(n>=2)
{
for(int i = 1; i <= n-2; i++)
{
string cur=res+f[0]+res+f[1]+f[0]+res+f[1]+f[1]+res+f[1]+f[2];
int x=press(cur);
if(x==res.size())
res+=f[2];
else if(x==(int)res.size()+1)
res+=f[0];
else res+=f[1];
}
string cur=res+f[0]+res+f[1];
if(press(cur)==res.size())
res+=f[2];
else
{
string tmp=res+f[0];
if(press(tmp)==res.size())
res+=f[1];
else res+=f[0];
}
}
return res;
}
