#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5 + 1;
vector<int> V;
bool P[MAXN];
int N, A[MAXN];
int main() {
  scanf("%d", &N);
  for (int i = 0; i < (int)N; i++) scanf("%d", &A[i]);
  for (int i = 0; i < (int)N; i++) {
    if (A[i] > N || P[A[i]])
      V.push_back(i);
    else
      P[A[i]] = true;
  }
  int k = 1;
  for (int i = 0; i < (int)V.size(); i++) {
    while (P[k]) k++;
    A[V[i]] = k;
    k++;
  }
  for (int i = 0; i < (int)N; i++) printf("%d ", A[i]);
  cout << endl;
}
