#include <bits/stdc++.h> #include <atcoder/all> using namespace std; using namespace atcoder; istream &operator>>(istream &is, modint &a) { long long v; is >> v; a = v; return is; } ostream &operator<<(ostream &os, const modint &a) { return os << a.val(); } istream &operator>>(istream &is, modint998244353 &a) { long long v; is >> v; a = v; return is; } ostream &operator<<(ostream &os, const modint998244353 &a) { return os << a.val(); } istream &operator>>(istream &is, modint1000000007 &a) { long long v; is >> v; a = v; return is; } ostream &operator<<(ostream &os, const modint1000000007 &a) { return os << a.val(); } typedef long long ll; typedef vector<vector<int>> Graph; typedef pair<int, int> pii; typedef pair<ll, ll> pll; #define FOR(i,l,r) for (int i = l;i < (int)(r); i++) #define rep(i,n) for (int i = 0;i < (int)(n); i++) #define all(x) x.begin(), x.end() #define rall(x) x.rbegin(), x.rend() #define my_sort(x) sort(x.begin(), x.end()) #define my_max(x) *max_element(all(x)) #define my_min(x) *min_element(all(x)) template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } const int INF = (1<<30) - 1; const ll LINF = (1LL<<62) - 1; const int MOD = 998244353; const int MOD2 = 1e9+7; const double PI = acos(-1); vector<int> di = {1,0,-1,0}; vector<int> dj = {0,1,0,-1}; #ifdef LOCAL # include <debug_print.hpp> # define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__) #else # define debug(...) (static_cast<void>(0)) #endif int main(){ cin.tie(0); ios_base::sync_with_stdio(false); int N; cin >> N; vector<ll> A(N), B(N - 1); rep(i, N) cin >> A[i]; sort(all(A)); rep(i, N - 1) cin >> B[i]; sort(all(B)); debug(A, B); vector<ll> d(N - 1), e(N - 1); rep(i, N - 1) { d[i] = abs(A[i] - B[i]); e[i] = abs(A[i + 1] - B[i]); } vector<int> accd(N), acce(N); rep(i, N - 1){ accd[i + 1] = accd[i] + d[i]; acce[i + 1] = acce[i] + e[i]; } ll ans = LINF; vector<int> L; rep(i, N){ ll acc = accd[i] + (acce[N - 1] - acce[i]); debug(acc, accd[i], (acce[N - 1] - acce[i])); if(chmin(ans, acc)) L.clear(); if(acc == ans){ L.push_back(A[i]); } } sort(all(L)); L.erase(unique(all(L)), L.end()); int T = L.size(); cout << T << endl; rep(i, T) cout << L[i] << (i == T - 1 ? "\n" : " "); }