#include <bits/stdc++.h>
using namespace std;
long long int minn(long long int a, long long int b) {
  if (a > b) return b;
  return a;
}
long long int maxx2(long long int a, long long int b) {
  if (a > b) return a;
  return b;
}
long long int maxx(long long int a, long long int b, long long int c) {
  return maxx2(a, maxx2(b, c));
}
long long int gcdd(long long int a, long long int b) {
  if (b == 0)
    return a;
  else
    return gcdd(b, a % b);
}
long long int dsum(long long int n) {
  long long int sum = 0;
  while (n > 0) {
    sum += n % 10;
    n /= 10;
  }
  return sum;
}
long long int poww(long long int a, long long int b) {
  if (b == 0) return 1;
  if (b == 1)
    return a;
  else
    return ((poww(a, b / 2) % 998244353) * (poww(a, b / 2) % 998244353) *
            (poww(a, b % 2) % 998244353)) %
           998244353;
}
long long int temp[200001] = {0};
long long int bs(long long int x, long long int l, long long int r,
                 long long int n) {
  if (l == r) {
    return l;
  }
  long long int mid = (l + r) / 2;
  if (temp[mid] == x) return mid;
  if (temp[mid] < x && temp[mid + 1] > x) return mid;
  if (temp[mid] < x)
    return bs(x, mid, r, n);
  else
    return bs(x, l, mid, n);
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long int n;
  cin >> n;
  long long int a[n];
  for (long long int i = 0; i < n; i++) {
    cin >> a[i];
  }
  long long int count = 0;
  for (long long int i = n - 1; i >= 0; i--) {
    for (long long int j = 0; j < i; j++) {
      if (a[j] == a[i]) a[j] = 0;
    }
    if (a[i] != 0) count++;
  }
  cout << count << endl;
  for (long long int i = 0; i < n; i++) {
    if (a[i] != 0) cout << a[i] << " ";
  }
  return 0;
}
