#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("-ffloat-store")
#pragma GCC optimize("-fno-defer-pop")
long long int power(long long int a, long long int b, long long int m) {
  if (b == 0) return 1;
  if (b == 1) return a % m;
  long long int t = power(a, b / 2, m) % m;
  t = (t * t) % m;
  if (b & 1) t = ((t % m) * (a % m)) % m;
  return t;
}
long long int modInverse(long long int a, long long int m) {
  return power(a, m - 2, m);
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int i, j, k, l, n;
  cin >> n;
  long long int ar[n], an[n];
  vector<long long int> vc;
  for (i = 0; i < n; i++) {
    cin >> ar[i];
  }
  long long int fl[200001] = {0};
  for (i = 0; i < n; i++) {
    if (fl[ar[i]] == 0 && ar[i] <= n) {
      fl[ar[i]] = 1;
      an[i] = ar[i];
    } else {
      vc.push_back(i);
    }
  }
  j = 0;
  for (i = 1; i <= n; i++) {
    if (fl[i] == 0) {
      an[vc[j]] = i;
      j++;
    }
  }
  for (i = 0; i < n; i++) {
    cout << an[i] << " ";
  }
  return 0;
}
