#include <bits/stdc++.h>
using namespace std;
int arr[100005];
int main() {
  int n, j = 1;
  scanf("%d", &n);
  int ara[n];
  for (int i = 0; i < n; i++) {
    scanf("%d", &ara[i]);
    if (arr[ara[i]] != 0 || ara[i] > n) ara[i] = -1;
    arr[ara[i]]++;
  }
  for (int i = 0; i < n; i++) {
    if (ara[i] == -1) {
      while (arr[j] != 0) j++;
      ara[i] = j;
      arr[j] = 1;
    }
  }
  for (int i = 0; i < n; i++) printf("%d ", ara[i]);
}
