// #include <iostream>
#include "combo.h"
using namespace std;
// int press(string x){
// return 0;
// }
string guess_sequence(int N) {
string x = "ABXY";
string S = "";
int cost = press("AB");
if(cost != 0){
cost = press("A");
if(cost == 1) S += 'A';
else S += 'B';
}else{
cost = press("X");
if(cost == 1) S += 'X';
else S += 'Y';
}
if(S[0] == 'A') x = "BXY";
else if(S[0] == 'B') x = "AXY";
else if(S[0] == 'X') x = "ABY";
else x = "ABX";
for(int i = 1; i < N; i++){
string p = "";
for(int j = 0; j < 3; j++) p+= S + x[0] + x[j];
p+= S + x[1];
cost = press(p);
if(cost-i == 2) S += x[0];
else if(cost-i == 1) S += x[1];
else S += x[2];
}
if(N > 1){
cost = press(S+x[0]);
if(cost == N){
S += x[0];
}else{
cost = press(S+x[1]);
if(cost == N){
S += x[1];
}else{
S+=x[2];
}
}
}
return S;
}
// int main(){
// }
