#include <bits/stdc++.h>
using namespace std;
void quickly_quickly_kro() {
  long long n;
  cin >> n;
  vector<long long> v(n);
  for (long long i = 0; i < n; i++) cin >> v[i];
  ;
  map<long long, long long> M, N, I;
  for (long long i = 0; i < n; i++) {
    if (v[i] != 0)
      M[v[i]]++;
    else
      I[i]++;
  }
  for (long long i = 1; i < n + 1; i++) {
    if (M[i] == 0) {
      N[i]++;
    }
  }
  for (auto k : I) {
    if ((N.find(k.first + 1) != N.end())) {
      auto it = N.find(k.first + 1);
      if (it != N.begin())
        it--;
      else
        it++;
      v[k.first] = it->first;
      N.erase(it);
    }
  }
  for (long long i = 0; i < n; i++) {
    if (v[i] == 0) {
      auto it = N.begin();
      pair<long long, long long> p = *it;
      v[i] = p.first;
      N.erase(it);
    }
  }
  for (long long i = 0; i < n; i++) cout << v[i] << " ";
}
signed main() {
  std::ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long t;
  t = 1;
  while (t--) {
    quickly_quickly_kro();
    cout << "\n";
    ;
  }
  return 0;
}
