/*
_____________________.
|____________________| $$\ $$\ $$\ $$\
|____________________| $$ | \__| $$ | $$ |
|____________________| $$$$$$\ $$$$$$\ $$$$$$\ $$$$$$$\ $$$$$$$\ $$$$$$\ $$\ $$$$$$\ $$$$$$$\ $$$$$$\ $$$$$$$\
|____________________| \_$$ _| $$ __$$\ \____$$\ $$ __$$\ $$ _____| $$ __$$\ $$ |$$ __$$\ $$ __$$\\_$$ _| $$ _____|
|____________________| $$ | $$ | \__|$$$$$$$ |$$ | $$ |\$$$$$$\ $$ | \__|$$ |$$ / $$ |$$ | $$ | $$ | \$$$$$$\
$$ |$$\ $$ | $$ __$$ |$$ | $$ | \____$$\ $$ | $$ |$$ | $$ |$$ | $$ | $$ |$$\ \____$$\
\$$$$ |$$ | \$$$$$$$ |$$ | $$ |$$$$$$$ | $$ | $$ |\$$$$$$$ |$$ | $$ | \$$$$ |$$$$$$$ |
へ ♡ \____/ \__| \_______|\__| \__|\_______/ \__| \__| \____$$ |\__| \__| \____/ \_______/
૮ - ՛) $$\ $$ |
/ ⁻ ៸| \$$$$$$ | are human rights :3
乀 (ˍ,ل ل \______/
*/
#include "combo.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag,
tree_order_statistics_node_update>;
template <typename T>
using ordered_multiset = tree<pair<T, long long>, null_type,
less<pair<T, long long>>, rb_tree_tag,
tree_order_statistics_node_update>;
#define ll int
#define ull unsigned long long
#define ld long double
#define inf (ll)1e13+31
#define pb push_back
#define se second
#define fi first
#define endl '\n'
#define mp make_pair
#define pll pair<ll,ll>
#define kth_smallest find_by_order
#define num_of_smaller order_of_key
#define fori(x) for(ll i=0;i<x;i++)
#define forj(y) for(ll j=0;j<y;j++)
//#define DEBUG
#ifdef DEBUG
#define show(x) cerr<<#x<<" is "<<x<<endl;
#define show2(x,y) cerr<<#x<<" is "<<x<<" "<<#y<<" is "<<y<<endl;
#define show3(x,y,z) cerr<<#x<<" is "<<x<<" "<<#y<<" is "<<y<<" "<<#z<<" is "<<z<<endl;
#define show4(x,y,z,a) cerr<<#x<<" is "<<x<<" "<<#y<<" is "<<y<<" "<<#z<<" is "<<z<<" "<<#a<<" is "<<a<<endl;
#define show_vec(a) for(auto &i:a)cerr<<i<<" ";cerr<<endl;
#define skillissue cerr<<"your code is running\n";
#define getchar_unlocked _getchar_nolock // comment before submission
#else
#define show(x)
#define show2(x,y)
#define show3(x,y,z)
#define show4(x,y,z,a)
#define show_vec(a)
#define skillissue
#endif
/*
inline int readint() {
int x=0; char ch=getchar_unlocked(); bool s=1;
while(ch<'0'||ch>'9'){if(ch=='-')s=0;ch=getchar_unlocked();}
while(ch>='0'&&ch<='9'){x=(x<<3)+(x<<1)+ch-'0';ch=getchar_unlocked();}
return s?x:-x;
}
*/
string guess_sequence(int N) {
string p = "";
vector<char> chars = {'A', 'B', 'X', 'Y'};
ll qry1 = press("AB");
ll qry2 = press("BX");
if(mp(qry1, qry2) == mp(0,0)){
p = "Y";
} else if(mp(qry1, qry2) == mp(1,0)){
p = "A";
} else if(mp(qry1, qry2) == mp(0,1)){
p = "X";
} else if(mp(qry1, qry2) == mp(1,1)){
p = "B";
} else if(mp(qry1, qry2) == mp(2,0)){
p = "AB";
} else if(mp(qry1, qry2) == mp(1,2)){
p = "BX";
}
chars = {};
if('A'!=p[0])chars.pb('A');
if('B'!=p[0])chars.pb('B');
if('X'!=p[0])chars.pb('X');
if('Y'!=p[0])chars.pb('Y');
while(p.length() < N-1){
string eee = p + chars[0] + p + chars[1] + chars[1] + p + chars[1] + chars[2] + p + chars[1] + chars[0];
ll qry = press(eee);
if(qry == p.length())p += chars[2];
else if(qry == p.length()+1)p += chars[0];
else p += chars[1];
}
if(p.length()==N)return p;
if(press(p+chars[0])==N)return p+chars[0];
if(press(p+chars[1])==N)return p+chars[1];
return p+chars[2];
}
