#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
using ll = long long;
using vi = vector<long long>;
#define pb emplace_back
std::string guess_sequence(int N) {
char start;
if(press("A"))
start = 'A';
else if (press("B"))
start = 'B';
else if(press("X"))
start = 'C';
else
start = 'Y';
string res;
res += start;
set<char> moves{'A', 'B', 'X', 'Y'};
moves.erase(start);
vector<char> left;
for(auto x : moves)
left.pb(x);
for(int i = 1; i < N - 1; ++i) {
string curr = res + left[0] + res + left[1] + left[0] + res + left[1] + left[1] + res + left[1] + left[2];
ll gain = press(curr);
int X = res.size();
if(gain == X + 1) {
res += (left[0]);
} else if(gain == X + 2) {
res += (left[1]);
} else {
res += (left[2]);
}
}
ll curr = press(res);
for(auto i : left) {
ll gain = press(res + i);
if(gain > curr) {
res += i;
break;
}
}
return res;
}
