#define _CRT_SECURE_NO_WARNINGS
#include "bits/stdc++.h"
//#include "libs.h"
#include <random>
#include <unordered_map>
#include <unordered_set>
//#include <opencv2/core.hpp>
//#include <opencv2/highgui.hpp>
//#include <opencv2/imgproc.hpp>

using namespace std;

//呪文
#define DUMPOUT cerr
#define dump(...) DUMPOUT<<"  ";DUMPOUT<<#__VA_ARGS__<<" :["<<__LINE__<<":"<<__FUNCTION__<<"]"<<endl;DUMPOUT<<"    ";dump_func(__VA_ARGS__)

typedef unsigned uint; typedef long long ll; typedef unsigned long long ull; typedef pair<int, int> pii; typedef pair<ll, ll> pll; typedef pair<double, double> pdd; typedef pair<string, string> pss;
template <typename _KTy, typename _Ty> ostream& operator << (ostream& o, const pair<_KTy, _Ty>& m) { o << "{" << m.first << ", " << m.second << "}"; return o; }
template <typename _KTy, typename _Ty> ostream& operator << (ostream& o, const map<_KTy, _Ty>& m) { if (m.empty()) { o << "{ }"; return o; } o << "{" << *m.begin(); for (auto itr = ++m.begin(); itr != m.end(); itr++) { o << ", " << *itr; } o << "}"; return o; }
template <typename _KTy, typename _Ty> ostream& operator << (ostream& o, const unordered_map<_KTy, _Ty>& m) { if (m.empty()) { o << "{ }"; return o; } o << "{" << *m.begin(); for (auto itr = ++m.begin(); itr != m.end(); itr++) { o << ", " << *itr; } o << "}"; return o; }
template <typename _Ty> ostream& operator << (ostream& o, const vector<_Ty>& v) { if (v.empty()) { o << "{ }"; return o; } o << "{" << v.front(); for (auto itr = ++v.begin(); itr != v.end(); itr++) { o << ", " << *itr; } o << "}"; return o; }
template <typename _Ty> ostream& operator << (ostream& o, const set<_Ty>& s) { if (s.empty()) { o << "{ }"; return o; } o << "{" << *(s.begin()); for (auto itr = ++s.begin(); itr != s.end(); itr++) { o << ", " << *itr; } o << "}"; return o; }
template <typename _Ty> ostream& operator << (ostream& o, const unordered_set<_Ty>& s) { if (s.empty()) { o << "{ }"; return o; } o << "{" << *(s.begin()); for (auto itr = ++s.begin(); itr != s.end(); itr++) { o << ", " << *itr; }	o << "}"; return o; }
template <typename _Ty> ostream& operator << (ostream& o, const stack<_Ty>& s) { if (s.empty()) { o << "{ }"; return o; } stack<_Ty> t(s); o << "{" << t.top(); t.pop(); while (!t.empty()) { o << ", " << t.top(); t.pop(); } o << "}";	return o; }
template <typename _Ty> ostream& operator << (ostream& o, const list<_Ty>& l) { if (l.empty()) { o << "{ }"; return o; } o << "{" << l.front(); for (auto itr = ++l.begin(); itr != l.end(); ++itr) { o << ", " << *itr; } o << "}"; return o; }
template <typename _KTy, typename _Ty> istream& operator >> (istream& is, pair<_KTy, _Ty>& m) { is >> m.first >> m.second; return is; }
template <typename _Ty> istream& operator >> (istream& is, vector<_Ty>& v) { for (size_t i = 0; i < v.size(); i++) is >> v[i]; return is; }
namespace aux { // print tuple
	template<typename Ty, unsigned N, unsigned L> struct tp { static void print(ostream& os, const Ty& v) { os << get<N>(v) << ", "; tp<Ty, N + 1, L>::print(os, v); } };
	template<typename Ty, unsigned N> struct tp<Ty, N, N> { static void print(ostream& os, const Ty& v) { os << get<N>(v); } };
}
template<typename... Tys> ostream& operator<<(ostream& os, const tuple<Tys...>& t) { os << "{"; aux::tp<tuple<Tys...>, 0, sizeof...(Tys)-1>::print(os, t); os << "}"; return os; }

template<typename A, size_t N, typename T> inline void Fill(A(&array)[N], const T &val) { std::fill((T*)array, (T*)(array + N), val); }

void dump_func() { DUMPOUT << endl; }
template <class Head, class... Tail> void dump_func(Head&& head, Tail&&... tail) { DUMPOUT << head; if (sizeof...(Tail) == 0) { DUMPOUT << " "; } else { DUMPOUT << ", "; } dump_func(std::move(tail)...); }

#define PI 3.14159265358979323846
#define EPS 1e-10
#define FOR(is,a,n) for(int is=(a);is<(n);++is)
#define REP(is,n)  FOR(is,0,n)
#define all(j) (j).begin(), (j).end()
#define SZ(j) ((int)(j).size())
#define fake false



const int NIL = -1;

template<typename T> void printVec(const vector<T>& v, char delim = ' ', ostream& os = cout) {
	os << v[0];
	for (int i = 1; i < v.size(); i++)
		os << delim << v[i];
	os << endl;
}

typedef struct Node {
	int id;
	int parent;
	int left, right;
	int sibling;
	int degree;
	int depth;
	int height;
	string attr;
	Node() : parent(NIL), left(NIL), right(NIL), sibling(NIL) {}
}* NodePtr;

ostream& operator<<(ostream& os, const Node& obj) {
	cout << "node " << obj.id << ": ";
	cout << "parent = " << obj.parent << ", ";
	cout << "sibling = " << obj.sibling << ", ";
	cout << "degree = " << obj.degree << ", ";
	cout << "depth = " << obj.depth << ", ";
	cout << "height = " << obj.height << ", ";
	cout << obj.attr;
	return os;
}

vector<Node> nodes;

// 返り値: 最深 depth
int calcAttributes(int v, int depth) {

	if (nodes[v].parent == NIL)
		nodes[v].attr = "root";
	else if (nodes[v].left == NIL && nodes[v].right == NIL)
		nodes[v].attr = "leaf";
	else
		nodes[v].attr = "internal node";

	nodes[v].degree = (nodes[v].left == NIL ? 0 : 1) + (nodes[v].right == NIL ? 0 : 1);
	
	nodes[v].depth = depth;

	int deepest = depth;
	if (nodes[v].left != NIL)
		deepest = max(deepest, calcAttributes(nodes[v].left, depth + 1));
	if (nodes[v].right != NIL)
		deepest = max(deepest, calcAttributes(nodes[v].right, depth + 1));
	
	nodes[v].height = deepest - depth;

	return deepest;
}

void preOrder(int v) {
	if (v == NIL)
		return;
	cout << " " << v;
	preOrder(nodes[v].left);
	preOrder(nodes[v].right);
}

void inOrder(int v) {
	if (v == NIL)
		return;
	inOrder(nodes[v].left);
	cout << " " << v;
	inOrder(nodes[v].right);
}

void postOrder(int v) {
	if (v == NIL)
		return;
	postOrder(nodes[v].left);
	postOrder(nodes[v].right);
	cout << " " << v;
}

int main() {
	
	cin.tie(0);
	ios::sync_with_stdio(false);

	int n;
	cin >> n;

	nodes.resize(n);

	for (int i = 0; i < n; i++) {
		int id, left, right;
		cin >> id >> left >> right;
		nodes[id].id = id;
		nodes[id].left = left;
		nodes[id].right = right;
		if (left != NIL) {
			nodes[left].parent = id;
			nodes[left].sibling = right;
		}
		if (right != NIL) {
			nodes[right].parent = id;
			nodes[right].sibling = left;
		}
	}

	int root;
	for (int i = 0; i < n; i++)
		if (nodes[i].parent == NIL)
			root = i;

	cout << "Preorder" << endl;
	preOrder(root);
	cout << endl;
	cout << "Inorder" << endl;
	inOrder(root);
	cout << endl;
	cout << "Postorder" << endl;
	postOrder(root);
	cout << endl;

	return 0;
}



Measured memory_bytes: 3124