#include "bits/stdc++.h"
#include "combo.h"
using namespace std;
#define ff first
#define ss second
#define all(v) v.begin(), v.end()
#define ll long long
#define pb push_back
#define pii pair<int, int>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define tr(i, c) for(auto i = c.begin(); i != c.end(); ++i)
#define wr puts("----------------")
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
int n;
string first_Letter_A(){
string ans = "A";
int x = 0;
for(int i = 2; i < n; ++i){
int s = (int)ans.size();
x = press(ans+"X"+ans+"BX"+ans+"BB"+ans+"BY");
if(x == s+1)
ans += "X";
else if(x == s+2)
ans += "B";
else
ans += "Y";
}
if(press(ans+"B") == n)
ans += "B";
else if(press(ans+"X") == n)
ans += "X";
else
ans += "Y";
return ans;
}
string first_Letter_B(){
string ans = "B";
int x = 0;
for(int i = 2; i < n; ++i){
int s = (int)ans.size();
x = press(ans+"X"+ans+"AX"+ans+"AA"+ans+"AY");
if(x == s+1)
ans += "X";
else if(x == s+2)
ans += "A";
else
ans += "Y";
}
if(press(ans+"A") == n)
ans += "A";
else if(press(ans+"X") == n)
ans += "X";
else
ans += "Y";
return ans;
}
string first_Letter_X(){
string ans = "X";
int x = 0;
for(int i = 2; i < n; ++i){
int s = (int)ans.size();
x = press(ans+"A"+ans+"BA"+ans+"BB"+ans+"BY");
if(x == s+1)
ans += "A";
else if(x == s+2)
ans += "B";
else
ans += "Y";
}
if(press(ans+"A") == n)
ans += "A";
else if(press(ans+"B") == n)
ans += "B";
else
ans += "Y";
return ans;
}
string first_Letter_Y(){
string ans = "Y";
int x = 0;
for(int i = 2; i < n; ++i){
int s = (int)ans.size();
x = press(ans+"A"+ans+"BA"+ans+"BB"+ans+"BX");
if(x == s+1)
ans += "A";
else if(x == s+2)
ans += "B";
else
ans += "X";
}
if(press(ans+"B") == n)
ans += "B";
else if(press(ans+"X") == n)
ans += "X";
else
ans += "A";
return ans;
}
string guess_sequence(int N){
n = N;
if(n == 1){
string ans = "";
if(press("A"))
ans += "A";
else if(press("B"))
ans += "B";
else if(press("X"))
ans += "X";
else
ans += "Y";
return ans;
}
if(press("AB")){
if(press("A"))
return first_Letter_A();
else
return first_Letter_B();
}
else{
if(press("X"))
return first_Letter_X();
else
return first_Letter_Y();
}
assert(false);
}
