#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
string guess_sequence(int N) {
char let[4] = {'A', 'B', 'X', 'Y'};
int banidx = -1;
string p = "";
p += let[0];
if (press(p) == 1) banidx = 0;
else {
for (int i = 1; i < 4; i++) {
p[0] = let[i];
if (press(p) == 1) {
banidx = i;
break;
}
}
}
for (int i = 1; i < N; i++) p += 'A';
int before = 0;
for (int i = 1; i < N; i++) {
for (int j = 0; j < 4; j++) {
if (j == banidx) continue;
for (int k = i; k < N; k++) p[k] = let[j];
int coin = press(p);
if (coin > i) {
i = coin;
break;
}
}
}
return p;
}
