#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, s, e) for (int i = (int)(s); i < (int)(e); ++i)
#define all(a) (a).begin(),(a).end()

int main() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    
    int N;
    cin >> N;
    vector<int> A(N), B(N - 1);
    rep(i, 0, N) cin >> A[i];
    rep(i, 0, N - 1) cin >> B[i];
    
    sort(all(A));
    sort(all(B));
    
    vector<ll> L(N, 0), R(N, 0);
    rep(i, 0, N - 1) L[i] = abs(A[i] - B[i]);
    rep(i, 1, N) R[i] = abs(A[i] - B[i - 1]);
    
    rep(i, 1, N) L[i] += L[i - 1];
    rep(i, 1, N) R[N - i - 1] += R[N - i];
    
    ll mini = 1ll << 60;
    set<int> s;
    rep(i, 0, N) {
        ll res;
        if (i == 0) res = R[i + 1];
        else if (i == N - 1) res = L[i - 1];
        else res = R[i + 1] + L[i - 1];
        
        if (res == mini) s.insert(A[i]);
        if (res < mini) {
            mini = res;
            s.clear();
            s.insert(A[i]);
        }
    }
    
    cout << s.size() << '\n';
    for (ll t : s) cout << t << ' ';
    cout << '\n';
}