#include <combo.h>
#include <bits/stdc++.h>
using namespace std;
string guess_sequence(int n) {
vector<string>ask(4,"");
string s="";
char lost;
if(press("AB")) {
if(press("A")) s+='A',ask[0]+='B',ask[1]="XY",ask[2]="XB",ask[3]="XX";
else s+='B',ask[0]+='A',ask[1]="XA",ask[2]="XY",ask[3]="XX";
} else {
if(press("X")) s+='X',ask[0]+='B',ask[1]="AA",ask[2]="AB",ask[3]="AY";
else s+='Y',ask[0]+='B',ask[1]="XA",ask[2]="XB",ask[3]="XX";
}
for(int i = 1 ; i < n ; i++) {
int cnt = press(s+ask[0]+s+ask[1]+s+ask[2]+s+ask[3]);
if(cnt == i) {
s+=lost;
} else if(cnt == i+1) {
s+=ask[0];
} else s+=ask[1][0];
}
return s;
}
