#include <bits/stdc++.h>   using namespace std;   int main() {     long long n, x, k;     cin >> n >> k;     vector<long long> v;     set<long long> s;     map<long long, long long> m;     for (long long i = 0; i < n; i++) {       cin >> x;       if (m[x] == 0) {         m[x]++;         v.insert(v.begin(), x);       }       if (v.size() > k) {         m[v.back()] = 0;         v.pop_back();       }     }     long long a = v.size();     cout << min((a), k) << endl;     for (long long i = 0; i < v.size(); i++) {       cout << v[i] <<    ;     }   }   