#include <bits/stdc++.h>
int const MAX = 1e5 + 5;
int a[MAX], need[MAX];
bool has[MAX], pos[MAX];
int main() {
  int n, num = 0;
  scanf("%d", &n);
  memset(has, false, sizeof(has));
  memset(pos, false, sizeof(pos));
  for (int i = 0; i < n; i++) {
    scanf("%d", &a[i]);
    if (!has[a[i]] && a[i] <= n)
      has[a[i]] = true;
    else
      pos[i] = true;
  }
  int cnt = 0;
  for (int i = 1; i <= n; i++)
    if (!has[i]) need[cnt++] = i;
  int idx = 0;
  for (int i = 0; i < n; i++)
    if (pos[i]) a[i] = need[idx++];
  for (int i = 0; i < n - 1; i++) printf("%d ", a[i]);
  printf("%d\n", a[n - 1]);
}
