#include <bits/stdc++.h>
using namespace std;
int main() {
  int arr[100000 + 1];
  int n, a;
  set<int> s;
  cin >> n;
  vector<bool> vst(n, false);
  for (int i = 0; i < n; ++i) {
    cin >> a;
    arr[i] = a;
    s.insert(a);
  }
  int k = 1;
  if (n != 1)
    for (int i = 0; i < n; ++i) {
      int j = arr[i];
      if (!vst[j] && j <= n) {
        vst[j] = 1;
        cout << j << " ";
      } else {
        while (s.count(k) || vst[k]) {
          k++;
        }
        vst[k] = true;
        cout << k << " ";
        k++;
      }
    }
  else
    cout << '1';
}
