//#include "combo.h"
#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
char used[4] = {'A', 'B', 'X', 'Y'};
string guess_sequence(int N) {
string ans;
char No;
int val;
val = press("AB");
if(val == 2) {
No = 'A';
ans += 'A';
}
else if(val == 1) {
val = press("A");
if(val == 1) {
No = 'A';
ans += 'A';
}
else {
No = 'B';
ans += 'B';
}
}
else {
val = press("X");
if(val == 1) {
No = 'X';
ans += 'X';
}
else {
No = 'Y';
ans += 'Y';
}
}
if(N == 1) return ans;
vector<char> vt;
for(int i=0; i<4; i++) {
if(No == used[i]) continue;
vt.push_back(used[i]);
}
for(int i=1; i<N-1; i++) {
string s1 = ans+vt[0]+vt[0], s2 = ans+vt[0]+vt[1], s3 = ans+vt[0]+vt[2], s4 = ans + vt[1];
int tmp = press(s1+s2+s3+s4);
if(tmp-i== -1) {
ans += vt[2];
}
else if(tmp == i) {
ans += vt[1];
}
else {
ans += vt[0];
}
}
bool fg = 0;
for(int i=0; i<2; i++) {
if(press(ans + vt[i]) == N) {
fg = 1;
ans+= vt[i];
break;
}
}
if(!fg) ans += vt[2];
return ans;
}
