/* -*- coding: utf-8 -*-
 *
 * 3016.cc:  No.3016 繝上メ繝槭く縺翫§縺輔ｓ - yukicoder
 */

#include<cstdio>
#include<vector>
#include<algorithm>

using namespace std;

/* constant */

const int MAX_N = 200000;
const long long LINF = 1LL << 62;

/* typedef */

using ll = long long;
using vi = vector<int>;

/* global variables */

int as[MAX_N], bs[MAX_N];
ll fds[MAX_N], bds[MAX_N];

/* subroutines */

/* main */

int main() {
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", as + i);
  for (int i = 0; i < n - 1; i++) scanf("%d", bs + i);

  sort(as, as + n);
  sort(bs, bs + n - 1);

  for (int i = 0; i < n - 1; i++)
    fds[i + 1] = fds[i] + abs(as[i] - bs[i]);
  bds[n - 1] = 0;
  for (int i = n - 2; i >= 0; i--)
    bds[i] = bds[i + 1] + abs(as[i + 1] - bs[i]);

  ll mins = LINF;
  vi ls;
  for (int i = 0; i < n; i++) {
    ll s = fds[i] + bds[i];
    if (mins > s)
      mins = s, ls.assign(1, as[i]);
    else if (mins == s)
      ls.push_back(as[i]);
  }
  //printf(" mins=%lld\n", mins);

  sort(ls.begin(), ls.end());
  ls.erase(unique(ls.begin(), ls.end()), ls.end());

  int t = ls.size();
  printf("%d\n", t);
  for (int i = 0; i < t; i++)
    printf("%d%c", ls[i], (i + 1 < t) ? ' ' : '\n');

  return 0;
}