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

using ll = long long;

int main(){
    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];
    }
    vector<int> ans;
    ll now =0;
    sort(a.begin(),a.end());
    sort(b.begin(),b.end());
    for(int i=0;i<n-1;i++){
        now += abs(a[i+1]-b[i]);
    }
    ll mi = now;
    ans.push_back(a[0]);
    for(int i=0;i<n-1;i++){
        now += abs(a[i]-b[i]);
        now -= abs(a[i+1]-b[i]);
        if(now < mi){
            ans.clear();
            mi = now;
        }
        else if(now > mi)continue;
        ans.push_back(a[i+1]);
    }
    sort(ans.begin(),ans.end());
    ans.erase(unique(ans.begin(),ans.end()),ans.end());
    cout << ans.size() << endl;
    for (int i:ans){
        cout << i << " ";
    }
    cout << endl;
    return 0;
}