/*input
*/
#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<double,double> pdd;
#define IOS ios_base::sync_with_stdio(0); cin.tie(0)
#define ALL(a) a.begin(),a.end()
#define SZ(a) ((int)a.size())
#define F first
#define S second
#define REP(i,n) for(int i=0;i<((int)n);i++)
#define pb push_back
#define MP(a,b) make_pair(a,b)
#define SORT_UNIQUE(c) (sort(c.begin(),c.end()), c.resize(distance(c.begin(),unique(c.begin(),c.end()))))
#define GET_POS(c,x) (lower_bound(c.begin(),c.end(),x)-c.begin())
template<typename T1,typename T2>
ostream& operator<<(ostream& out,pair<T1,T2> P){
out<<'('<<P.F<<','<<P.S<<')';
return out;
}
//}}}
const ll maxn=2005;
const ll maxlg=__lg(maxn)+2;
const ll INF64=8000000000000000000LL;
const int INF=0x3f3f3f3f;
const ll MOD=ll(1e9+7);
const double PI=acos(-1);
//const ll p=880301;
//const ll P=31;
char c[]={'A','B','X','Y'};
string s[3];
// int press(string s){
// cout<<s<<'\n';
// int ret;
// cin>>ret;
// return ret;
// }
string guess_sequence(int n){
string ans;
{
int tmp=press("AB");
if(tmp){
int meow=press("A");
if(meow) ans.pb('A');
else ans.pb('B');
}
else{
int meow=press("X");
if(meow) ans.pb('X');
else ans.pb('Y');
}
}
{
int pt=0;
REP(i,4){
if(c[i]==ans[0]) continue;
s[pt++].pb(c[i]);
}
}
for(int i=1;i<n-1;i++){
int tmp=press(ans+s[0]+ans+s[1]+s[0]+ans+s[1]+s[1]+ans+s[1]+s[2]);
if(tmp==SZ(ans)) ans.pb(s[2][0]);
else if(tmp==SZ(ans)+1) ans.pb(s[0][0]);
else ans.pb(s[1][0]);
}
if(press(ans+s[0])==SZ(ans)+1) ans=ans+s[0];
else if(press(ans+s[1])==SZ(ans)+1) ans=ans+s[1];
else ans=ans+s[2];
return ans;
}
// int main()
// {
// int n;
// cin>>n;
// guess_sequence(n);
// return 0;
// }
