#include <bits/stdc++.h>
#define fr(i, n, m) for(int i = (n); i < (m); i ++)
#define pb push_back
#define st first
#define nd second
#define pq priority_queue
#define all(x) begin(x),end(x)
#define what_is(x) cout<<#x<<' '<<x<<endl
#include "combo.h"
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
ll const inf = 1e9;
ll const mod = 1e9 + 7;
ld const eps = 1e-9;
string guess_sequence(int N) {
string s = "";
if(press("AB") > 0){
if(press("A") == 1) s += 'A';
else s += 'B';
}
else{
if(press("X") == 1) s += 'X';
else s += 'Y';
}
if(N == 1) return s;
vector<string> buttons = {"A", "B", "X", "Y"};
fr(i, 0, 4){
if(s == buttons[i]){
buttons.erase(buttons.begin() + i);
break;
}
}
string attach[4];
attach[0] = buttons[0] + buttons[0];
attach[1] = buttons[0] + buttons[1];
attach[2] = buttons[0] + buttons[2];
attach[3] = buttons[1];
int len = 1;
fr(i, 1, N - 1){
int ans = press(s + attach[0] + s + attach[1] + s + attach[2] + s + attach[3]);
if(ans == len) s += buttons[2];
else if(ans == len + 1) s += buttons[1];
else s += buttons[0];
len ++;
}
if(press(s + buttons[0] + s + buttons[1]) == N){
if(press(s + buttons[0]) == N){
s += buttons[0];
}
else{
s += buttons[1];
}
}
else{
s += buttons[2];
}
return s;
}
