#include <bits/stdc++.h>   using namespace std;   auto fio = (ios::sync_with_stdio(0), cin.tie(0), cout.tie(0));   int32_t main() {     long long n;     cin >> n;     vector<long long> g(n);     for (long long& x : g) cin >> x;     vector<vector<long long>> idx(8192);     for (long long i = 0; i < n; i++) idx[g[i]].push_back(i);     vector<long long> mn(8192, n);     mn[0] = -1;     for (long long i = 0; i <= 5000; i++) {       if (idx[i].empty()) continue;       for (long long j = 0; j < 8192; j++) {         if (mn[j] <= mn[i ^ j] || mn[i ^ j] >= idx[i].back()) continue;         auto it = upper_bound(idx[i].begin(), idx[i].end(), mn[i ^ j]);         if (it != idx[i].end() && *it < mn[j]) mn[j] = *it;       }     }     cout << 8192 - count(mn.begin(), mn.end(), n) << endl;     for (long long i = 0; i < 8192; i++)       if (mn[i] != n) cout << i <<    ;     cout << endl;   }   