#include<bits/stdc++.h>
#include<combo.h>
using namespace std;
string guess_sequence(int n){
char c;string ans;
vector<char> ch;
if(press("AB")){
if(press("A")) c='A';
else c='B';
}
else{
if(press("X")) c='X';
else c='Y';
}
if(c!='A') ch.push_back('A');
if(c!='B') ch.push_back('B');
if(c!='X') ch.push_back('X');
if(c!='Y') ch.push_back('Y');
ans.push_back(c);
for(int i=2;i<=n-1;i++){
int a=press(ans+ch[0]+ch[0]+ans+ch[0]+ch[1]+ans+ch[0]+ch[2]+ans+ch[1]+ch[0]);
if(a==i+1) ans.push_back(ch[0]);
else if(a==i) ans.push_back(ch[1]);
else ans.push_back(ch[2]);
}
if(press(ans+ch[0])) return (ans+ch[0]);
else if(press(ans+ch[1])) return (ans+ch[1]);
else return ans+ch[2];
}
