#include <bits/stdc++.h>
using namespace std;
bool comparator(const std::pair<int, int>& l, const std::pair<int, int>& r) {
  return l.first < r.first;
}
int main(int narg, char** args) {
  int n, v;
  char mark[1000000];
  std::pair<int, int> e;
  vector<int> list;
  vector<int> idx;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> v;
    list.push_back(v);
  }
  for (int i = 0; i < n; i++) {
    if ((list[i] - 1) < n && mark[list[i] - 1] != 'x') {
      mark[list[i] - 1] = 'x';
    } else
      idx.push_back(i);
  }
  int x = 0;
  for (int i = 0; i < n; i++) {
    if (mark[i] != 'x') {
      list[idx[x++]] = i + 1;
    }
  }
  for (int i = 0; i < n; i++) cout << list[i] << " ";
  return 0;
}
