#include <bits/stdc++.h>
using namespace std;
const int mod = 1000000007;
struct custom_hash {
  static uint64_t splitmix64(uint64_t x) {
    x += 0x9e3779b97f4a7c15;
    x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
    x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
    return x ^ (x >> 31);
  }
  size_t operator()(uint64_t x) const {
    static const uint64_t FIXED_RANDOM =
        chrono::steady_clock::now().time_since_epoch().count();
    return splitmix64(x + FIXED_RANDOM);
  }
};
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int t, n, m, k, q, x, a, b, c, d, w;
  cin >> n >> k;
  vector<int> V(n);
  unordered_map<int, int, custom_hash> L;
  for (auto &it : V) {
    cin >> it;
  }
  vector<int> ans(2 * n);
  int j = 1;
  for (int i = 0; i < n; i++) {
    if (j - L[V[i]] > k || L[V[i]] == 0) {
      L[V[i]] = j;
      ans[j] = V[i];
      j++;
    }
  }
  cout << j - max(j - k, 1) << "\n";
  for (int i = j - 1; i >= max(j - k, 1); i--) {
    cout << ans[i] << " ";
  }
  cout << "\n";
  return 0;
}
