#include <bits/stdc++.h>
#include "transfer.h"
#define ll long long
#define co cout<<
//#pragma GCC optimize("O3,Ofast,unroll-loops")
//#pragma GCC target("avx2,sse3,sse4,avx")
using namespace std;
//stuff
vector<int>get_attachment(vector<int>source){
vector<int>arr;
ll num=0;
ll pa=0;
for(int i=0;i<255;i++){
if(source[i]) num^=i+1;
pa^=source[i];
}
string s="";
while(num){
s+='0'+(num%2);
num>>=1;
}
reverse(s.begin(),s.end());
while(s.size()<8) s='0'+s;
for(auto i:s) arr.push_back(i-'0');
arr.push_back(pa);
return arr;
}
vector<int>retrieve(vector<int>data){
vector<int>arr=data;
ll pa,pa1,num;
pa=0,pa1=0,num=0;
ll test=arr[263];
vector<int>ans;
for(int i=255;i<263;i++){
num=num*2+arr[i];
}
for(int i=0;i<255;i++){
pa^=arr[i];
if(arr[i]) num^=i+1;
}
pa1=pa;
if(num){
if(arr[num-1]) pa1=((pa1-1)%2+2)%2;
else pa1=(pa1+1)%2;
if(pa1==test){
for(int i=0;i<255;i++){
ans.push_back(arr[i]);
}
ans[num-1]^=1;
return ans;
}
else{
for(int i=0;i<255;i++){
ans.push_back(arr[i]);
}
return ans;
}
}
else{
for(int i=0;i<255;i++){
ans.push_back(arr[i]);
}
return ans;
}
}
