#define _GLIBCXX_DEBUG
#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define rep0(N) for (int COUNTER = 0; COUNTER < (int)(N); COUNTER++)
#define rep(i, N) for (int i = 0; i < (int)(N); i++)
#define rep1(i, N) for (int i = 0; i < (int)(N); i++)
#define rep2(i, START, GOAL) for (int i = (int)(START); i < (int)(GOAL); i++)
#define rep3(i, START, GOAL) for (int i = (int)(START); i > (int)(GOAL); i--)
#define all(CONTAINER) CONTAINER.begin(), CONTAINER.end()
#define rall(CONTAINER) CONTAINER.rbegin(), CONTAINER.rend()
#define from1(CONTAINER) CONTAINER.begin() + 1, CONTAINER.end()
#define rfrom1(CONTAINER) CONTAINER.rbegin(), CONTAINER.rend() - 1
#define pout(X) cout << X << " "
#define print(X) cout << X << "\n"
#define output(X) cout << X << "\n"
#define dbe(X) cerr << X << " "
#define dbel(X) cerr << X << "\n"
#define dberr(X) cerr << X << " "
#define dberrl(X) cerr << X << "\n"
#define db(X) cerr << #X << ":" << (X) << " "
#define dbl(X) cerr << #X << ":" << (X) << "\n"
#define db2(X, Y) cerr << #X << ":" << (X) << ", " << #Y << ":" << (Y) << " "
#define db2l(X, Y) cerr << #X << ":" << (X) << ", " << #Y << ":" << (Y) << "\n"
#define dbl2(X, Y) cerr << #X << ":" << (X) << "\n" << #Y << ":" << (Y) << "\n"
#define db3(X, Y, Z) cerr << #X << ":" << (X) << ", " << #Y << ":" << (Y) << " " << #Z << ":" << (Z) << " "
#define db3l(X, Y, Z) cerr << #X << ":" << (X) << ", " << #Y << ":" << (Y) << ", " << #Z << ":" << (Z) << "\n"
#define dbl3(X, Y, Z) cerr << #X << ":" << (X) << "\n" << #Y << ":" << (Y) << "\n" << #Z << ":" << (Z) << "\n"
#define dbp(PAIR) cerr << #PAIR << ":(" << PAIR.first << ", " << PAIR.second << ") "
#define dbpl(PAIR) cerr << #PAIR << ":(" << PAIR.first << ", " << PAIR.second << ")\n"
#define dbt3(TUPLE3) cerr << #TUPLE3 << ":(" << get<0>(TUPLE3) << ", " << get<1>(TUPLE3) << ", " << get<2>(TUPLE3) << ") "
#define dbt3l(TUPLE3) cerr << #TUPLE3 << ":(" << get<0>(TUPLE3) << ", " << get<1>(TUPLE3) << ", " << get<2>(TUPLE3) << ")\n"
#define dbt4(TUPLE4) cerr << #TUPLE4 << ":(" << get<0>(TUPLE4) << ", " << get<1>(TUPLE4) << ", " << get<2>(TUPLE4) << ", " << get<3>(TUPLE4) << ") "
#define dbt4l(TUPLE4) cerr << #TUPLE4 << ":(" << get<0>(TUPLE4) << ", " << get<1>(TUPLE4) << ", " << get<2>(TUPLE4) << ", " << get<3>(TUPLE4) << ")\n"
#define dbv(VEC) cerr << #VEC << ":{ "; for (auto ELEM : VEC) cerr << ELEM << ", "; cerr << "}\n"
#define dbvp(VP) cerr << #VP << ":{ "; for (auto PAIR : VP) cerr << "(" << PAIR.first << ", " << PAIR.second << "), "; cerr << "}\n"
#define dbvv(VV) cerr << #VV << ":{\n"; for (auto VEC : VV) { cerr << "{ "; for (auto ELEM : VEC) cerr << ELEM << ", "; cerr << "},\n"; } cerr << "}\n"
#define dbvvp(VVP) cerr << #VVP <<":{\n"; for (auto VP : VVP) { cerr << "{ "; for (auto PAIR : VP) { cerr << "(" << PAIR.first << ", " << PAIR.second << "), "; } cerr << "},\n"; } cerr << "}\n";
#define dbs(SET) cerr << #SET << "{ "; for (auto ELEM : SET) cerr << ELEM << ", "; cerr << "}\n";
#define dbsp(SP) cerr << #SP << "{ "; for (auto PAIR : SP) cerr << "(" << PAIR.first << ", " << PAIR.second << "), "; "}\n";
#define dbm(MAP) cerr << #MAP << ":{ "; for (auto PAIR : MAP) cerr << "(" << PAIR.first << ", " << PAIR.second << "), "; cerr << "}\n"
#define YN(f) cout << (f ? "YES" : "NO") << "\n"
#define Yn(f) cout << (f ? "Yes" : "No") << "\n"
#define yn(f) cout << (f ? "yes" : "no") << "\n"
using ll = long long;
using pii = pair<int, int>;using pll = pair<ll, ll>;using pdd = pair<double, double>;
using ti3 = tuple<int, int, int>;using tl3 = tuple<ll, ll, ll>;using td3 = tuple<double, double, double>;
using ti4 = tuple<int, int, int, int>;using tl4 = tuple<ll, ll, ll, ll>;using td4 = tuple<double, double, double, double>;
using vi = vector<int>;using vl = vector<ll>;using vd = vector<double>;using vs = vector<string>;using vb = vector<bool>;
using vvi = vector<vi>;using vvl = vector<vl>;using vvd = vector<vd>;using vvb = vector<vb>;
using vpii = vector<pii>;using vpll = vector<pll>;using vpdd = vector<pdd>;
using mii = map<int, int>;using mll = map<ll, ll>;
using si = set<int>;using sl = set<ll>;using ss = set<string>;
using spii = set<pii>;using spll = set<pll>;using spdd = set<pdd>;
// db

vi l, r;
vi pre, in, post;
vb seen;

void dfs(int u) {
	seen[u] = true;
	int left = l[u], right = r[u];
	pre.push_back(u);
	if (left != -1 and !seen[left]) {
		dfs(left);		
	}
	in.push_back(u);
	if (right != -1 and !seen[right]) {
		dfs(right);		
	}
	post.push_back(u);
}

int main() {
	int n; cin >> n;
	l.assign(n, -1), r.assign(n, -1);
	vb isroot(n, true);
	rep0(n) {
		int id, left, right; cin >> id >> left >> right;
		if (left != -1) {
			l[id] = left;
			isroot[left] = false;
		}
		if (right != -1) {
			r[id] = right;
			isroot[right] = false;
		}
	}
	// dbvv(g); dbv(l); dbv(r);
	int root;	rep(i, n) if (isroot[i]) root = i;
	// dbl(root);
	seen.assign(n, false); // reached		
	dfs(root);

	// dbl(root); dbv(l); dbv(r);
	// dbv(pre); dbv(in); dbv(post);

	cout << "Preorder" << endl;
	rep(i, n) cout << " " << pre[i]; cout << endl;
	cout << "Inorder" << endl;
	rep(i, n) cout << " " << in[i]; cout << endl;
	cout << "Postorder" << endl;
	rep(i, n) cout << " " << post[i]; cout << endl;
}



Measured memory_bytes: 3184