#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<long long> VL;
typedef vector<VL> VVL;
typedef long long LL;
#define all(a) (a).begin(), (a).end()
#define Yes(n) cout << ((n) ? "Yes" : "No"  ) << endl
#define ALL(a)  (a).begin(),(a).end()
#define pb push_back

int main() {
  int n;cin>>n;
  int A[n],B[n-1];
  rep(i,n){cin>>A[i];}
  rep(i,n-1){cin>>B[i];}
  sort(A,A+n); sort(B,B+n-1);
  map<LL,set<int>> ans;
  LL L[n-1],R[n-1];
  rep(i,n-1){L[i]=abs(A[i]-B[i]);}
  rep(i,n-1){R[i]=abs(A[i+1]-B[i]);}
  rep(i,n-2){L[i+1]+=L[i];}
  for(int i=n-3;i>=0;i--){R[i]+=R[i+1];}
  //rep(i,n-1){cout<<R[i]<<' ';}cout<<endl;
  rep(i,n){
    LL ss;
    if(i==0){ss=R[0];}
    else if(i==n-1){ss=L[n-2];}
    else{ss=L[i-1]+R[i];}
    //cout<<i<<' '<<ss<<endl;
    ans[ss].insert(A[i]);
  }
  auto it=*ans.begin();
  set<int> D=(it).second;
  cout<<D.size()<<endl;
  for(int it : D){
    cout<<it<<' ';
  }cout<<endl;
}