#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
istream &operator>>(istream &is, modint &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint &a) { return os << a.val(); }
istream &operator>>(istream &is, modint998244353 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint998244353 &a) { return os << a.val(); }
istream &operator>>(istream &is, modint1000000007 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint1000000007 &a) { return os << a.val(); } 

typedef long long ll;
typedef vector<vector<int>> Graph;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define FOR(i,l,r) for (int i = l;i < (int)(r); i++)
#define rep(i,n) for (int i = 0;i < (int)(n); i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define my_sort(x) sort(x.begin(), x.end())
#define my_max(x) *max_element(all(x))
#define my_min(x) *min_element(all(x))
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const int INF = (1<<30) - 1;
const ll LINF = (1LL<<62) - 1;
const int MOD = 998244353;
const int MOD2 = 1e9+7;
const double PI = acos(-1);
vector<int> di = {1,0,-1,0};
vector<int> dj = {0,1,0,-1};

#ifdef LOCAL
#  include <debug_print.hpp>
#  define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define debug(...) (static_cast<void>(0))
#endif

int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(false);
    int N; cin >> N;
    vector<ll> A(N), B(N - 1);
    rep(i, N) cin >> A[i];
    sort(all(A));
    rep(i, N - 1) cin >> B[i];
    sort(all(B));
    debug(A, B);

    vector<ll> d(N - 1), e(N - 1);
    rep(i, N - 1) {
        d[i] = abs(A[i] - B[i]);
        e[i] = abs(A[i + 1] - B[i]);
    }

    vector<int> accd(N), acce(N);
    rep(i, N - 1){
        accd[i + 1] = accd[i] + d[i];
        acce[i + 1] = acce[i] + e[i];
    }

    ll ans = LINF;
    vector<int> L;
    rep(i, N){
        ll acc = accd[i] + (acce[N - 1] - acce[i]);
        debug(acc, accd[i], (acce[N - 1] - acce[i]));
        if(chmin(ans, acc)) L.clear();
        if(acc == ans){
            L.push_back(A[i]);
        }
    }

    sort(all(L));
    L.erase(unique(all(L)), L.end());

    int T = L.size();
    cout << T << endl;
    rep(i, T) cout << L[i] << (i == T - 1 ? "\n" : " ");
}