#include <bits/stdc++.h>
using namespace std;

const int LOG_MAX = 20;
const int MAX = 1e5 + 7;
int N;
vector<pair<int, int>> edges;
vector<int> adj[MAX];

void input() {
	cin >> N;
	for (int t = 2 * N - 3; t--; ) {
		int u, v; cin >> u >> v;
		adj[u].push_back(v);
		adj[v].push_back(u);
		edges.emplace_back(u, v);
	}
}

vector<int> tree[MAX];
int up[LOG_MAX][MAX], tin[MAX], tout[MAX], depth[MAX], COUNTER;

void dfs(int u, int p = 0) {
	tin[u] = ++COUNTER;
	depth[u] = depth[p] + 1;
	up[0][u] = p;
	for (int j = 1; j < LOG_MAX; j++)
		up[j][u] = up[j - 1][up[j - 1][u]];

	for (int v : adj[u]) if (tin[v] == 0) {
		tree[u].push_back(v);
		dfs(v, u);
	}
	tout[u] = COUNTER;
}

inline bool is_ancestor(int u, int v) {
	return tin[u] <= tin[v] and tout[v] <= tout[u];
}

inline int lca(int u, int v) {
	if (is_ancestor(u, v))
		return u;
	if (is_ancestor(v, u))
		return v;

	for (int j = LOG_MAX - 1; j >= 0; j--) {
		if (up[j][v] == 0)
			continue;
		if (is_ancestor(up[j][v], u))
			continue;
		v = up[j][v];
	}
	return up[0][v];
}

void init() {
	COUNTER = 0;
	depth[0] = 0;
	memset(up, 0, sizeof up);
	memset(tin, 0, sizeof tin);
	memset(tout, 0, sizeof tout);
	for (int u = 1; u <= N; u++) if (tin[u] == 0)
		dfs(u);
}

inline int dist(int u, int v) {
	return depth[u] + depth[v] - 2 * depth[lca(u, v)];
}

void print_path(pair<int, int> e) {
	int u, v;
	tie(u, v) = e;
	
	int z = lca(u, v);
	vector<int> path_u, path_v;
	for (; u != z; u = up[0][u])
		path_u.push_back(u);
	for (; v != z; v = up[0][v])
		path_v.push_back(v);
	reverse(path_v.begin(), path_v.end());

	for (int u : path_u)
		cout << u << " ";
	cout << z << " ";
	for (int v : path_v)
		cout << v << " ";
	cout << endl;

}

pair<int, int> back_edges[MAX];

void solve() {
	for (int d = 0; d <= N; d++)
		back_edges[d] = make_pair(-1, -1);

	for (const auto &e : edges) {
		int u, v;
		tie(u, v) = e;
		if (up[0][u] == v or up[0][v] == u)
			continue;
		
		int d = dist(u, v);
		if (back_edges[d].first != -1) {
			cout << d + 1 << endl;
			print_path(e);
			print_path(back_edges[d]);
			return;
		}

		back_edges[d] = e;
	}

	cout << -1;
}
	
int main(void) {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);

	input();
	init();
	solve();

	return 0;
}