#include "transfer.h"
#include <bits/stdc++.h>
using namespace std;
vector<int> get_attachment(vector<int> source) {
int n = (int) source.size();
vector<int> ans;
for (int i = 0; (1 << i) < n; i++) {
ans.push_back(0);
for (int j = 1; j <= n; j++) {
if (j & (1 << i)) {
ans.back() = (ans.back() + source[j - 1]) % 2;
}
}
}
ans.push_back(accumulate(ans.begin(), ans.end(), 0) % 2);
return move(ans);
}
vector<int> retrieve(vector<int> data) {
int n = ((int) data.size() == 70 ? 63 : 255);
int x = 0;
for (int i = n; i < (int) data.size() - 1; i++) {
x = (x + data[i]) % 2;
}
if (x == data.back()) {
vector<int> tmp;
for (int i = 0; (1 << i) < n; i++) {
tmp.push_back(0);
for (int j = 1; j <= n; j++) {
if (j & (1 << i)) {
tmp.back() = (tmp.back() + data[j - 1]) % 2;
}
}
}
int k = 0;
for (int i = 0; (1 << i) < n; i++) {
if (tmp[i] != data[n + i]) {
k += (1 << i);
}
}
if (k > 0) {
data[k - 1] = !data[k - 1];
}
}
return vector<int>(data.begin(), data.begin() + n);
}
