geor

#include <bits/stdc++.h>

using namespace std;

/// se viziteaza radacina si apoi dupa fiecare subarbore vizitat se viziteaza din nou radacina(recursiv)

vector <int> L[1001];
int n, rad, t[1001], e[2002], len, x;

void Citire()
{
    cin >> n;
    for (int i = 1; i < n; i++)
        cin >> t[i];
}

int Radacina()
{
    for (int i = 1; i <=n; i++)
        if (t[i] == 0) return i;
    return n;
}

void FormareListeAd()
{
    for (int i = 1; i <= n; i++)
        if (t[i] != 0)
        {
            x = t[i]; /// avem muchia (x, i)
            L[x].push_back(i);
        }
}

void Euler(int k)
{
    e[++len] = k;
    for (auto i : L[k])
    {
        Euler(i);
        e[++len] = k;
    }
}

void Afisare()
{
    for(int i = 1; i <= len; i++)
        cout << e[i] << " ";
    cout << "\n\n";
}

int main()
{
    Citire();
    rad = Radacina();
    FormareListeAd();
    Euler(rad);
    Afisare();

    return 0;
}
/**
8
0 1 1 1 2 3 3 4
*/