#include "bits/stdc++.h"
#include "combo.h"
using namespace std;
std::string guess_sequence(int n) {
string pb = "ABXY";
string possibilities = "";
string p = "";
char prefix;
if (press("AB") > 0){
if (press("A") == 1) {p += 'A';}
else {p += 'B';}
} else if (press("X") == 1) {p += 'X';}
else {p+='Y';}
prefix=p[0];
for (int i=0;i<pb.size();++i){
if (pb[i]==prefix) {continue;}
possibilities+=pb[i];
}
int last_ans = 1;
while(last_ans<n-1)
{
string toAdd = "";
toAdd+=possibilities[0];
toAdd+=p;
toAdd+=possibilities[1];
for(int i=0;i<possibilities.size();++i){
toAdd+=possibilities[i];
if (i<possibilities.size()-1){
toAdd+=p;
toAdd+=possibilities[1];
}
}
int ans = press(p + toAdd);
if (ans-last_ans==1){
p+=possibilities[0];
} else if (ans-last_ans > 1){
p+=possibilities[1];
} else {
p+=possibilities[2];
}
++last_ans;
}
if(press(p + possibilities[0]) - last_ans == 1) {p+=possibilities[0];}
else if(press(p + possibilities[1]) - last_ans == 1) {p+=possibilities[1];}
else {p+=possibilities[2];}
return p;
}
