#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
#define fr(m,n,k) for(int m=n;m<=k;m++)
#define sz size()
#define all(v) v.begin(), v.end()
int n;
string guess_sequence(int N) {
n = N; string v = "ABXY"; string p, s; int a;
p = "AB";
int x = press(p);
if (x) {
p = "A"; int x = press(p);
if (x == 1) a = 0;
else a = 1;
}
else {
p = "X"; int x = press(p);
if (x == 1) a = 2;
else a = 3;
}
s = v[a];
if (n == 1) return s;
vector<int> rem = {0, 1, 2, 3}; rem.erase(find(all(rem), a));
fr(i, 1, n - 2) {
p = "";
for (auto z : rem) p += s + v[rem[0]] + v[z];
p += s + v[rem[1]];
int x = press(p);
if (x == i) {
a = rem[2];
}
else if (x == i + 1) {
a = rem[1];
}
else {
a = rem[0];
}
s += v[a];
}
p = s + v[rem[0]] + s + v[rem[1]];
x = press(p);
if (x >= n) {
p = s + v[rem[0]]; int x = press(p);
if (x == n) a = rem[0];
else a = rem[1];
}
else {
a = rem[2];
}
s += v[a];
return s;
}
