#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
string guess_sequence(int n){
vector<string> b = {"A", "B", "X", "Y"};
string fi;
for (int i = 0; i < 4; i++){
fi = b[i];
if (i == 3) break;
int x = press(fi);
if (x == 1){
break;
}
}
vector<string> se;
for (auto i : b){
if (i != fi) se.push_back(i);
}
int lstx = 1;
string ans;
for (int i = 0; i < n - 1; i++){
string q1 = fi + ans + se[0] + fi;
string q2 = fi + ans + se[1] + fi;
int x1 = press(q1);
int x2 = press(q2);
if (x1 == lstx + 1){
ans += se[0];
}
else if (x2 == lstx + 1){
ans += se[1];
}
else {
ans += se[2];
}
lstx++;
}
return ans;
}
