#include "combo.h"
//ᴇᴀᴄʜ ᴘᴇʀꜱᴏɴ ᴡɪʟʟ ᴏɴʟʏ ʜᴀᴠᴇ ᴡʜᴀᴛ ᴛʜᴇʏ ᴇɴᴅᴇᴀᴠᴏᴜʀᴇᴅ ᴛᴏᴡᴀʀᴅꜱ [53:39]
//Author: Sazid Hasan
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef double dl;
typedef vector<int> vi;
typedef vector<vector<int>> vii;
typedef vector<ll> vl;
typedef vector<bool> vb;
typedef pair<int,int> pii;
typedef pair<ll, ll> pll;
#define ff first
#define ss second
#define all(a) a.begin(),a.end()
#define gcd(a,b) __gcd(a,b)
#define lcm(a,b) (a*(b/gcd(a,b)))
#define spc " "
#ifdef ONLINE_JUDGE
#define debarr(array)
#define deb(x)
#define del
#else
#define debarr(array) for(int w = 0; w < array.size(); w++) cerr << #array << "-" << w << " = " << array[w] << endl;
#define deb(x) cerr << #x << " = " << x << endl;
#define del cerr << '\n';
#endif
const double PI = acos(-1);
const int MOD = 1000000007;
const int inf = (2147483647);
std::string guess_sequence(int N) {
string s = "";
vector<char> ch = {'A', 'B', 'X', 'Y'};
int i;
for(i = 0; i < 3; i++){
int now = press(s+ch[i]);
if(now==1) break;
}
s = ch[i];
auto itr = find(all(ch), ch[i]);
ch.erase(itr);
for(i = 1; i < N-1; i++){
int now = press(s+ch[0] + s+ch[1]+ch[0] + s+ch[1]+ch[1] + s+ch[1]+ch[2]);
if(now==1+i) s.push_back(ch[0]);
else if(now==2+i) s.push_back(ch[1]);
else s.push_back(ch[2]);
}
for(auto x: ch){
int now = press(s+x);
if(now>(int)s.size()){
s.push_back(x);
break;
}
}
return s;
}
