#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
string guess_sequence(int N){
string ans;
vector<char> v;
if(press("A")){
ans+="A";
v.push_back('B');
v.push_back('X');
v.push_back('Y');
}
else if(press("B")){
ans+="B";
v.push_back('A');
v.push_back('X');
v.push_back('Y');
}
else if(press("X")){
ans+="X";
v.push_back('B');
v.push_back('A');
v.push_back('Y');
}
else {
ans+="Y";
v.push_back('B');
v.push_back('X');
v.push_back('A');
}
for(int i = 2; i <= N; ++i){
ans+="?";
for(int j = 0; j < 3; ++j){
ans[i-1] = v[j];
if(press(ans) == i)break;
}
}
return ans;
}
