#include<bits/stdc++.h>
#include<combo.h>
#define ll int
#define ld long double
#define fs first
#define sc second
#define debug(y) cout<<y,exit(0)
using namespace std;
typedef pair<ll,ll> LL;
const ll N = 3e5 + 9;
const ll inf = 1e9 + 7;
string p = "ABXY";
string guess_sequence(int n) {
int x;
string s;
char ch[4]= {'A', 'B', 'X', 'Y'};
if (press("AB") >= 1) x = press("A") != 1;
else x = 2 + (press("X") < 1);
s += ch[x];
if (n == 1) return s;
swap(ch[x], ch[3]);
for (int i = 1; i < n - 1; i++) {
x = press(s + ch[0] + ch[0] + s + ch[0] + ch[1] + s + ch[0] + ch[2] + s + ch[1]);
if (x == i + 2) s += ch[0];
else if (x == i + 1) s += ch[1];
else s += ch[2];
}
if (press(s + ch[0] + s + ch[1]) == n) {
if (press(s + ch[0]) == N) s += ch[0];
else s += ch[1];
}
else s += ch[2];
return s;
}
/*
int main(){
ios_base::sync_with_stdio(NULL); cin.tie(0); cout.tie(0);
#define task "tst"
if (fopen(task".inp","r")){
freopen(task".inp","r",stdin);
//freopen(task".out","w",stdout);
}
}
/// be confident
*/
