#include <bits/stdc++.h>
using namespace std;
std::vector<int> get_attachment(std::vector<int> v){
int xr = 0;
for (int i = 0; i < (int)v.size(); i++) xr ^= (i+1)*v[i];
int on = 0;
for (int i = 0; i < ((int)v.size()==63?6:8); i++){
v.push_back(xr^1);
on ^= (xr^1);
xr >>= 1;
}
v.push_back(on);
return v;
}
std::vector<int> retrieve(std::vector<int> v){
int n = ((int)v.size() < 100? 63 : 255);
int xr = 0;
std::vector<int> res;
for (int i = 0; i < n; i++){
xr ^= (i+1)*v[i];
res.push_back(v[i]);
}
int check = 0, on = 0;
for (int i = 0; i < (n==63?6:8); i++){
if (v[n+i]){
check ^= (1<<i);
on ^= 1;
}
}
if (xr != check && on == v.back()) res[(xr^check)-1] ^= 1;
return res;
}
