#include<bits/stdc++.h>
#include "combo.h"
using namespace std;
#define sz(x) (int)x.size()
#define pb push_back
#define fall(i,a,b) for(int i=a;i<=b;i++)
char get(string v,string s){
if(sz(v)==1) return v[0];
string l="",r="",t1="",t2="";
fall(i,0,sz(v)/2-1){
l+=s;
l+=v[i];
t1+=v[i];
}
fall(i,sz(v)/2,sz(v)-1){
r+=s;
r+=v[i];
t2+=v[i];
}
int x=press(l);
if(x>=sz(s)+1) return get(t1,s);
else return get(t2,s);
}
string guess_sequence(int n) {
char c=get("ABXY","");
string pos="ABXY";
string s="";
for(auto u:pos) if(u!=c) s+=u;
string ans=""; ans+=c;
fall(i,2,n-1){
string aux="";
fall(j,0,2) aux+=ans,aux+=s[0],aux+=s[j];
aux+=ans,aux+=s[1];
int x=press(aux);
if(x==i-1) ans+=s[2];
else if(x==i) ans+=s[1];
else ans+=s[0];
}
if(n!=1) ans+=get(s,ans);
return ans;
}
