#include <iostream>
#include <sstream>
#include <cstdlib>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <numeric>
#include <vector>
#include <string>
#include <set>
#include <map>
#include <deque>

using namespace std;
#define ll long long
void sherry()
{
    ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout);
#endif
}
/*bool comp(pair<int, int> a, pair<int, int> b)
{
    return a.second < b.second;
}*/
int main()
{
    sherry();
    ll n, count = 0;
    cin >> n;
    vector<int> v(0);
    deque<int> de;
    vector<int> fre(n + 1);
    for (ll i = 0; i < n; i++)
    {
        ll num;
        cin >> num;
        fre[num]++;
        v.push_back(num);
    }
    for (ll i = 1; i <= n; i++)
    {
        if (fre[i] == 0)
        {
            if (v[i - 1] == 0 && !de.empty())
            {
                v[i - 1] = de.back();
                de.pop_back();
            }
            de.push_back(i);
        }
    }
    for (ll i = 0; i < n; i++)
    {

        if (v[i] == 0)
        {
            if (de.back() == i + 1)
            {
                cout << de.front() << " ";
                de.pop_front();
            }
            else
            {
                cout << de.back() << " ";
                de.pop_back();
            }
        }
        else
        {
            cout << v[i] << " ";
        }
    }
}