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

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    ll N, minAns = LLONG_MAX;
    cin >> N;
    vector<ll> A(N), B(N - 1), L(N), R(N);
    set<ll> ans;
    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());
    for(int i=0; i<N-1; i++) L[i+1] = L[i] + abs(A[i] - B[i]);
    for(int i=N-1; i>0; i--) R[i-1] = R[i] + abs(A[i] - B[i-1]);
    for(int i=0; i<N; i++) {
        if(minAns >= L[i] + R[i]) {
            if(minAns > L[i] + R[i]) if(!ans.empty()) ans.clear();
            ans.insert(A[i]);
            minAns = L[i] + R[i];
        }
    }
    cout << ans.size() << endl;
    for(auto it=ans.begin(); it!=ans.end(); it++) cout << *it << " \n"[next(it) == ans.end()];
}