#include <fstream>
using namespace std;

ifstream fin("preordine.in");
ofstream fout("preordine.out");

struct nod{
    int val, st, dr;
}v[1001];

int n;

int radacina()
{
    int x[1001] = {0};
    for(int i=1; i<=n ;i++)
    {
        x[v[i].st] = 1;
        x[v[i].dr] = 1;
    }

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

void preordine(int k)
{
    if(k > 0)
    {
        fout << v[k].val << " ";
        preordine(v[k].st);
         preordine(v[k].dr);
    }

}

int main()
{
    fin >> n;
    for(int i=1; i<=n; i++)
    {
        fin >> v[i].val >> v[i].st >> v[i].dr;
    }

    preordine(radacina());

    return 0;
}