#include "transfer.h"
#include <bits/stdc++.h>
#define R(a) for (int i = 0; i < a; ++i)
using namespace std;
vector<int> get_attachment(vector<int> source) {
int chk = 0;
R((int)source.size()) if (source[i]) chk ^= (i + 1);
if (source.size() == 63) {
vector<int> ret(7);
R(6) ret[i] = (chk >> i) & 1;
R(6) ret[6] ^= ret[i];
return ret;
}
vector<int> ret(9);
R(8) ret[i] = (chk >> i) & 1;
R(8) ret[8] ^= ret[i];
return ret;
}
vector<int> retrieve(vector<int> data) {
if (data.size() <= 70) {
int fck = 0;
R(6) fck ^= data[data.size() - 7 + i];
if (fck != data[data.size() - 1]) return vector<int>(data.begin(), data.end()-7);
int chk = 0;
R((int)data.size() - 7) if (data[i]) chk ^= (i + 1);
int ick = 0;
R(6) ick += (data[data.size() - 7 + i] << i);
int diff = chk ^ ick;
if (diff) data[diff - 1] ^= 1;
return vector<int>(data.begin(), data.end()-7);
}
int fck = 0;
R(8) fck ^= data[data.size() - 9 + i];
if (fck != data[data.size() - 1]) return vector<int>(data.begin(), data.end()-9);
int chk = 0;
R((int)data.size() - 9) if (data[i]) chk ^= (i + 1);
int ick = 0;
R(8) ick += (data[data.size() - 9 + i] << i);
int diff = chk ^ ick;
if (diff) data[diff - 1] ^= 1;
return vector<int>(data.begin(), data.end()-9);
}
