#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int n;
  scanf("%d", &n);
  int a[n];
  for (int i = 0; i < n; i++) scanf("%d", a + i);
  int marked[100005] = {0};
  int visited[100005] = {0};
  for (int i = 0; i < n; i++) {
    if ((a[i] >= 1 && a[i] <= n) && !visited[a[i]]) {
      marked[i] = 1;
      visited[a[i]] = 1;
    }
  }
  int counter = 1;
  for (int i = 0; i < n; i++) {
    if (!marked[i]) {
      while (visited[counter]) counter++;
      a[i] = counter;
      visited[counter] = 1;
    }
  }
  for (int i = 0; i < n; i++) printf("%d ", a[i]);
  return 0;
}
