#include"bits/stdc++.h"
#include"combo.h"
using namespace std;
using ll=long long;
#define S second
#define F first
int q;
void qry(string s){
q=press(s);
}
string guess_sequence(int n){
string s;
qry("AB");
if(q==1)qry("A"),s+=(q?'A':'B');
else qry("X"),s+=(q?'X':'Y');
string val[3];q=0;
for(char c:"ABXY")if(c!=s[0])val[q++]=c;
for(int i=1;i<n-1;i++){
qry(s+val[0]+s+val[1]+val[0]+s+val[1]+val[1]+s+val[1]+val[2]);
if(q==0)s+=val[2];
else if(q==1)s+=val[0];
else s+=val[1];
}
qry(val[0]+val[1]);
if(q==1)qry(val[0]),s+=val[q];
else s+=val[2];
return s;
}
