#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i, j;
  cin >> n;
  int a[n + 1];
  int b[100001] = {0};
  int c[100001] = {0};
  for (i = 1; i <= n; i++) {
    cin >> a[i];
    b[a[i]]++;
    c[a[i]]++;
  }
  j = 1;
  for (i = 1; i <= n; i++) {
    if (b[a[i]] != 0 && a[i] <= n) {
      cout << a[i] << " ";
      b[a[i]] = 0;
    } else {
      while (j <= n && c[j] != 0) j++;
      cout << j << " ";
      j++;
    }
  }
  cout << endl;
  return 0;
}
