#include <bits/stdc++.h>
using namespace std;
using ll = long long;

#ifdef LOCAL
#include <debug.hpp>
#else
#define debug(...)
#endif

constexpr ll INF = 1LL << 60;

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);
    int N;
    cin >> N;
    vector<int> A(N), B(N - 1);
    for (int i = 0; i < N; i++) cin >> A[i];
    for (int i = 0; i < N - 1; i++) cin >> B[i];
    sort(A.begin(), A.end());
    sort(B.begin(), B.end());

    // left[i] := [0, i) の不満度
    // right[i] := [i, N) の不満度
    vector<ll> left(N), right(N);
    for (int i = 0; i < N - 1; i++) {
        left[i + 1] = left[i] + abs(A[i] - B[i]);
    }
    for (int i = N - 2; i >= 0; i--) {
        right[i] = right[i + 1] + abs(A[i + 1] - B[i]);
    }

    // i 番目のハチマキを残したときの不満度の最小値
    ll ans = INF;
    for (int i = 0; i < N; i++) {
        ans = min(ans, left[i] + right[i]);
    }

    // 残す可能性のあるハチマキの集合 L
    vector<int> L;
    for (int i = 0; i < N; i++) {
        if (ans == left[i] + right[i]) L.emplace_back(A[i]);
    }
    sort(L.begin(), L.end());
    L.erase(unique(L.begin(), L.end()), L.end());

    int T = L.size();
    cout << T << '\n';
    for (int i = 0; i < T; i++) {
        cout << L[i] << " \n"[i == T - 1];
    }
}