#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
string guess_sequence(int N) {
string answer;
// Step 1: find first character
// 2 queries
char first_char;
if (press("AB") > 0) {
if (press("A") > 0) first_char = 'A';
else first_char = 'B';
} else {
if (press("X") > 0) first_char = 'X';
else first_char = 'Y';
}
string nonfirst = "ABXY";
nonfirst.erase(find(nonfirst.begin(), nonfirst.end(), first_char));
answer.push_back(first_char);
// Step 2: find second character
// 3 queries
for (int i = 0; i < 3; i++) {
int query_result = press(answer + string(N, nonfirst[i]));
answer = answer + string(query_result-(int)answer.size(), nonfirst[i]);
}
// Step 3: find other characters
while (answer.size() < N) {
string all_next = "ABXY";
all_next.erase(find(all_next.begin(), all_next.end(), first_char));
all_next.erase(find(all_next.begin(), all_next.end(), answer.back()));
if (rand()%2) swap(all_next[0], all_next[1]);
int query_result = press(answer + string(N, all_next[0]));
if (query_result > (int)answer.size()) {
answer = answer + string(query_result-(int)answer.size(), all_next[0]);
} else {
int query_result_2 = press(answer + string(N, all_next[1]));
answer = answer + string(query_result_2-(int)answer.size(), all_next[1]);
}
}
return answer;
}
