#include "combo.h"
#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
using ll = long long;
#define all(x) x.begin(), x.end()
#define oset tree<ll, null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update>
string guess_sequence(int n){
string p = "";
if(press("AB") >= 1)p = (press("A") ? "A" : "B");
else p = (press("X") ? "X" : "Y");
vector<char> a = {'A', 'B', 'X', 'Y'};
a.erase(find(all(a), p[0]));
while((int)p.size() <= n - 2){
int q = press(p + a[0] + a[0] + p + a[0] + a[1] + p + a[1] + a[0]);
if(q == p.size()){
p.push_back(a[2]);
}else if(q == p.size() + 1){
q = press(p + a[1] + a[2]);
if(q == p.size()) p = p + a[0] + a[2];
else if(q == p.size() + 1) p = p + a[1] + a[1];
else p = p + a[1] + a[2];
}else{
q = press(p + a[0] + a[1]);
if(q == p.size())p = p + a[1] + a[0];
else if(q == p.size() + 1)p = p + a[0] + a[0];
else p = p + a[0] + a[1];
}
}
while(p.size() != n){
if(press(p + a[0]) == p.size() + 1)p.push_back(a[0]);
else if(press(p + a[1]) == p.size() + 1)p.push_back(a[1]);
else p.push_back(a[2]);
}
return p;
}
//int main(){
// ios::sync_with_stdio(false);
// cin.tie(0);
// //ifstream cin("cycle2.in");
// //ofstream cout("cycle2.out");
//}
