#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
//using mint = modint1000000007;
using ll = long long;
ll INF = 2e18;
template<typename T> using vc = vector<T>;
template<typename T> using vv = vc<vc<T>>;
using vi = vc<int>; using vvi = vv<int>;
using vl = vc<ll>; using vvl = vv<ll>;
using vs = vc<string>; using vvs = vv<string>;
using vb = vc<bool>; using vvb = vv<bool>;
using vmint = vc<mint>; using vvmint = vv<mint>;
#define rep(i,n) for(ll i=0; i<(n); i++)
#define drep(i,n) for(ll i=(n)-1; i>=0; i--)
#define rrep(i,n) for(ll i=1; i<=(n); i++)
#define nfor(i,a,b) for(ll i=a;i<b;i++)
#define dfor(i,a,b) for(ll i=(a)-1; i>=(b); i--)
template<class T>istream& operator>>(istream& i, vc<T>& v) {rep(j,(ll) size(v))i >> v[j]; return i; }
#define nall(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define chmax(x,y) x = max(x,y)
#define chmin(x,y) x = min(x,y)
#define YES cout<<"Yes"<<endl
#define NO cout<<"No"<<endl
#define YN {YES;}else{NO;}
#define ERROR cout<<-1<<endl
void print(long double x){ printf("%.20Lf\n",x);}
#define vc_cout(v){ll n = size(v);rep(i,n)cout<<v[i]<<endl;}
#define vv_cout(v){ll n = size(v);rep(i,n){rep(j,size(v[i])){cout<<' '<<v[i][j];}cout<<endl;}}

int main(){
    ll N;
    cin >> N;
    vl A(N), B(N-1);
    rep(i,N) cin >> A[i];
    rep(i,N-1) cin >> B[i];
    sort(nall(A));
    sort(nall(B));
    vl upsum(N);
    vl downsum(N);
    rep(i,N-1) {
        upsum[i+1] = upsum[i] + abs(A[i] - B[i]);
    }
    drep(i,N-1) {
        downsum[i] = downsum[i+1] + abs(A[i+1] - B[i]);
    }
    ll bad = INF;
    set<ll> ans;
    rep(i,N) {
        if (bad == upsum[i] + downsum[i]) {
            ans.insert(A[i]);
        } else if (bad > upsum[i] + downsum[i]) {
            ans.clear();
            ans.insert(A[i]);
        }
        chmin(bad,upsum[i]+downsum[i]);
    }
    int ans_size = ans.size();
    cout << ans_size << endl;
    for (auto a : ans) cout << a << " ";
    cout << endl;
}