#include <iostream>
#include <cmath>
#include <algorithm>
#include <string>
#include <vector>
#include <map>
#include <unordered_map>
#include <queue>
#include <set>
#include <unordered_set>
#include <complex>
#include <list>
#include <cassert>
#include <chrono>
#include <random>
#include <stack>
#include <iomanip>
#include <fstream>
using namespace std;
#define endl "\n"
// #define int long long
const int INF = 1e9+7;
const int MOD = 1e9+7;
// int press(string p){cout << p << " "; int nr; cin >> nr; return nr;};
int press(string p);
string guess_sequence(int n){
assert(n != 1);
string sol;
vector<char> ops;
if(press("AB")){
if(press("A")){
sol += 'A';
ops = {'B', 'X', 'Y'};
} else {
sol += 'B';
ops = {'A', 'X', 'Y'};
}
} else {
if(press("X")){
sol += 'X';
ops = {'A', 'B', 'Y'};
} else {
sol += 'Y';
ops = {'A', 'B', 'X'};
}
}
if(n == 1) return sol;
while(sol.size() < n-1){
int ans = press(sol+ops[0]+ops[0]+sol+ops[0]+ops[1]+sol+ops[0]+ops[2]+sol+ops[1]);
if(ans == sol.size()+2){
sol += ops[0];
} else if(ans == sol.size()+1){
sol += ops[1];
} else {
sol += ops[2];
}
}
if(press(sol+"AB") > sol.size()){
if(press(sol+'A') > sol.size()) sol += 'A';
else sol += 'B';
} else {
if(press(sol+'X') > sol.size()) sol += 'X';
else sol += 'Y';
}
return sol;
}
