tijie

#include<bits/stdc++.h>
using namespace std;
struct tree{
    int lchild,rchild;
}t[100001];
int n;
void qian(int x){
    if(x==0) return;
    cout<<x<<" ";
    qian(t[x].lchild);
    qian(t[x].rchild);
}
void zhong(int x){
    if(x==0) return;
    zhong(t[x].lchild);
    cout<<x<<" ";
    zhong(t[x].rchild);
    
}
void hou(int x){
    if(x==0) return;
    hou(t[x].lchild);
    hou(t[x].rchild);
    cout<<x<<" ";
}
int main(){
    cin>>n;
    int a,j,k;
    for(int i=1;i<=n;i++){
        cin>>a>>j>>k;
        t[a].lchild=j;
        t[a].rchild=k;
    }
    qian(1);
    cout<<endl;
    zhong(1);
    cout<<endl;
    hou(1);
    cout<<endl;
    return 0;
}