#include <bits/stdc++.h>
using namespace std;
using ll = int64_t;
int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    int N;
    cin >> N;
    vector<int> A(N);
    vector<int> 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());
    vector<int> ans;
    ll pref = 0, suff = 0;
    for(int i = 1; i < N; i++) suff += abs(A[i] - B[i - 1]);
    ll val = pref + suff;
    ans.push_back(A[0]);
    for(int i = 1; i < N; i++) {
        suff -= abs(A[i] - B[i - 1]);
        pref += abs(A[i - 1] - B[i - 1]);
        ll cur = pref + suff;
        if(cur <= val) {
            if(cur == val) {
                ans.push_back(A[i]);
                continue;
            }
            ans.clear();
            ans.push_back(A[i]);
            val = cur;
        }
    }
    sort(ans.begin(), ans.end());
    ans.erase(unique(ans.begin(), ans.end()), ans.end());
    cout << ans.size() << '\n';
    for(int i = 0; i < (int)ans.size(); i++) cout << ans[i] << " \n"[i == (int)ans.size() - 1];
}