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

#define For(i, a, b) for(int i = (a); i < (b); i++)
#define rep(i, n) For(i, 0, n)
#define rFor(i, a, b) for(int i = (a); i >= (b); i--)
#define ALL(v) (v).begin(), (v).end()
#define rALL(v) (v).rbegin(), (v).rend()

using lint = long long;
using ld = long double;

int INF = 2000000000;
lint LINF = 1000000000000000000;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    cin >> n;
    vector<lint> a(n), b(n - 1);
    rep(i, n) {
        cin >> a[i];
    }
    rep(i, n - 1) {
        cin >> b[i];
    }
    sort(ALL(a));
    sort(ALL(b));
    lint init = 0;
    rep(i, n - 1) {
        init += abs(a[i + 1] - b[i]);
    }
    lint unsat = init;
    lint cur = unsat;
    For(i, 1, n) {
        cur -= abs(a[i] - b[i - 1]);
        cur += abs(a[i - 1] - b[i - 1]);
        unsat = min(unsat, cur);
    }
    
    set<lint> ans;
    lint now = init;
    rep(i, n) {
        if (i > 0) {
            now -= abs(a[i] - b[i - 1]);
            now += abs(a[i - 1] - b[i - 1]);
        }
        if (now == unsat) {
            ans.insert(a[i]);
        }
    }
    cout << ans.size() << "\n";
    for (auto x : ans) {
        cout << x << " ";
    }
    cout << "\n";
}