#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
string guess_sequence(int n) {
char f;
string s;
s = "AB";
int Q = 0;
int q = press(s);
Q++;
if(q == 2) f = 'A';
else if(q == 1) {
s = "A";
Q++;
if(press(s) == 1) f = 'A';
else f = 'B';
} else {
s = "X";
Q++;
if(press(s) == 1) f = 'X';
else f = 'Y';
}
char c[4] = {'A', 'B', 'X', 'Y'};
if(f == 'B') swap(c[1], c[0]);
else if(f == 'X') swap(c[2], c[0]);
else if(f == 'Y') swap(c[3], c[0]);
s = "";
for(int i = 0; i < 4*n; i++) s += c[0];
for(int i = 1; i < n-1; i++) {
s[i] = s[i+n] = s[i+2*n] = c[1];
s[i+1] = c[1];
s[i+1+n] = c[2];
s[i+1+2*n] = c[3];
s[i+3*n] = c[2];
Q++;
int x = press(s);
if(x == i+2) s[i] = s[i+n] = s[i+2*n] = s[i+3*n] = c[1];
else if(x == i+1) s[i] = s[i+n] = s[i+2*n] = s[i+3*n] = c[2];
else s[i] = s[i+n] = s[i+2*n] = s[i+3*n] = c[3];
}
if(n > 1) {
s[n-1] = 'A';
s[2*n-1] = 'B';
s[3*n-1] = 'A';
s[4*n-1] = 'B';
Q++;
q = press(s);
if(q == n) {
s[2*n-1] = s[4*n-1] = 'A';
Q++;
if(press(s) != n) s[n-1] = 'B';
} else {
s[n-1] = s[2*n-1] = s[3*n-1] = s[4*n-1] = 'X';
Q++;
if(press(s) != n) s[n-1] = 'Y';
}
}
string t = "";
for(int i = 0; i < n; i++) t += s[i];
assert(Q <= n+2);
return t;
}
