$emm~$

#include<iostream>
using namespace std;
struct node
{
    int v;
    int l,r;
};
node tree[1000005];
void xxbl(int i)
{
    if(i==0)
    {
        return;
    }
    cout<<tree[i].v<<" ";
    xxbl(tree[i].l);
    xxbl(tree[i].r);
}
void zxbl(int i)
{
    if(i==0)
    {
        return;
    }
    zxbl(tree[i].l);
    cout<<tree[i].v<<" ";
    zxbl(tree[i].r);
}
void hxbl(int i)
{
    if(i==0)
    {
        return;
    }
    hxbl(tree[i].l);
    hxbl(tree[i].r);
    cout<<tree[i].v<<" ";
}
int main()
{
    int n;
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        tree[i].v=i;
        cin>>tree[i].l>>tree[i].v;
    }
    xxbl(1);
    cout<<endl;
    zxbl(1);
    cout<<endl;
    hxbl(1);
    cout<<endl;
    return 0;
}