#include "bits/stdc++.h"
#include "combo.h"
using namespace std;
#define ll long long
string guess_sequence(int n) {
string s = "", c = "ABXY";
if(press("AB")) {
if(press(string(1, 'A'))) {
s = "A";
} else {
s = "B";
}
} else {
if(press(string(1, 'X'))) {
s = "X";
} else {
s = "Y";
}
}
int idx = c.find(s[0]);
c.erase(idx, 1);
for(int i=1;i<n-1;++i) {
string p = s + c[0] + s + c[1] + c[0] + c[0] + s + c[1] + c[1] + c[0] + s + c[1] + c[0] + c[2];
int res = press(p);
if(res == i) {
s += c[2];
} else if(res == i + 1) {
s += c[0];
} else {
s += c[1];
}
}
if(n != 1 && press(s + c[0] + c[1]) == n) {
if(press(s + c[0]) == n) {
s += c[0];
} else {
s += c[1];
}
} else if(n != 1) {
s += c[2];
}
return s;
}
