#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
string guess_sequence(int N){
int n = N, x;
string s;
set <char> let;
let.insert({'A', 'B', 'X', 'Y'});
char ch = 0;
x = press(s + 'A' + s + 'B');
if(x == 1){
x = press(s + 'A');
if(x == 0) ch = 'B';
else ch = 'A';
}
else{
x = press(s + 'X');
if(x == 0) ch = 'Y';
else ch = 'X';
}
s.push_back(ch);
let.erase(ch);
set <char> :: iterator it = let.begin();
char A, B, C;
A = *it; ++it; B = *it; ++it; C = *it;
for(int i = 2; i < n ; ++i){
int x = press(s + A + s + B + A + s + B + B + s + B + C);
if(x == 0) s.push_back(C);
else if(x == 1) s.push_back(A);
else if(x == 2) s.push_back(B);
}
ch = 0;
x = press(s + 'A' + s + 'B');
if(x == 1){
x = press(s + 'A');
if(x == 0) ch = 'B';
else ch = 'A';
}
else{
x = press(s + 'X');
if(x == 0) ch = 'Y';
else ch = 'X';
}
s.push_back(ch);
return s;
}
