/*************************************
*    author: marvinthang             *
*    created: 18.11.2024 10:41:51    *
*************************************/

#include <bits/stdc++.h>

using namespace std;

#define             fi  first
#define             se  second
#define           left  ___left___
#define          right  ___right___
#define   scan_op(...)  istream & operator >> (istream &in, __VA_ARGS__ &u)
#define  print_op(...)  ostream & operator << (ostream &out, const __VA_ARGS__ &u)
#define     file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
#ifdef LOCAL
    #include "debug.h"
#else
    #define DB(...)
    #define db(...) ""
    #define debug(...)
#endif

namespace std {
template <class U, class V> scan_op(pair <U, V>) { return in >> u.first >> u.second; }
template <class T> scan_op(vector <T>) { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class U, class V> print_op(pair <U, V>) { return out << '(' << u.first << ", " << u.second << ')'; }
template <size_t i, class T> ostream &print_tuple_utils(ostream &out, const T &tup) { if constexpr(i == tuple_size<T>::value) return out << ")"; else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); }
template <class...U> print_op(tuple <U...>) { return print_tuple_utils<0, tuple <U...>>(out, u); }
template <class Con, class = decltype(begin(declval<Con>()))>typename enable_if <!is_same<Con, string>::value, ostream &>::type operator << (ostream &out, const Con &con) { out << '{'; for (__typeof(con.begin()) it = con.begin(); it != con.end(); ++it) out << (it == con.begin() ? "" : ", ") << *it; return out << '}'; }
template <class T> print_op(stack <T>) { vector <T> v; stack <T> st = u; while (!st.empty()) v.push_back(st.top()), st.pop(); reverse(v.begin(), v.end()); return out << v; }
template <class T> print_op(queue <T>) { queue <T> q = u; out << '{'; while (!q.empty()) { out << q.front(); q.pop(); if (!q.empty()) out << ", "; } out << '}'; return out; }
template <class T, class X, class Y> print_op(priority_queue <T, X, Y>) { priority_queue <T, X, Y> pq = u; out << '{'; while (!pq.empty()) { out << pq.top(); pq.pop(); if (!pq.empty()) out << ", "; } out << '}'; return out; }
template <class Fun> class y_combinator_result { Fun fun_; public: template <class T> explicit y_combinator_result(T &&fun): fun_(forward<T>(fun)) {} template <class...Args> decltype(auto)operator()(Args &&...args) { return fun_(ref(*this), forward<Args>(args)...); } };
template <class Fun> decltype(auto)y_combinator(Fun &&fun) { return y_combinator_result<decay_t<Fun>>(forward<Fun>(fun)); }
template <typename T, int D> struct Vec: public vector <Vec<T, D - 1>> { static_assert(D >= 1, "Vector dimension must be greater than zero!"); template <typename ...Args> Vec(int n = 0, Args ...args): vector <Vec<T, D - 1>>(n, Vec<T, D - 1>(args...)) {} };
template <typename T> struct Vec<T, 1>: public vector<T>{ Vec(int n = 0, const T &val = T()): vector<T>(n, val) {} };
#if __cplusplus < 202002L
    template <class T> int ssize(const T &a) { return a.size(); }
#endif
}

void process(void) {
    int n; cin >> n;
    Vec <int, 2> adj(n);
    vector<int> deg(n);
    for (int i = 0; i < 2 * n - 3; ++i) {
        int u, v; cin >> u >> v; --u; --v;
        adj[u].emplace_back(v);
        adj[v].emplace_back(u);
        deg[u]++, deg[v]++;
    }
    vector<int> vis(n);
    vector<int> depth(n), par(n, -1);
    queue<int> q;
    vector<int> ord(n);
    iota(ord.begin(), ord.end(), 0);
    sort(ord.begin(), ord.end(), [&](int u, int v) { return deg[u] > deg[v]; });
    for (int root : ord) {
        if (vis[root]) continue;
        vis[root] = 1;
        q.emplace(root);
        while (q.size()) {
            int u = q.front(); q.pop();
            for (int v: adj[u]) {
                if (vis[v]) continue;
                vis[v] = 1;
                depth[v] = depth[u] + 1;
                par[v] = u;
                q.push(v);
            }
        }
    }
    auto extract_cycle = [&](int x, int y) {
        vector<int> l, r;
        while (depth[x] > depth[y]) {
            l.push_back(x);
            x = par[x];
        }
        while (depth[y] > depth[x]) {
            r.push_back(y);
            y = par[y];
        }
        while (x != y) {
            l.push_back(x);
            r.push_back(y);
            x = par[x];
            y = par[y];
        }
        l.push_back(x);
        reverse(r.begin(), r.end());
        for (int v: r) l.push_back(v);
        return l;
    };
    vector<vector<int>> cycle(n + 1);
    for (int i = 0; i < n; i++) {
        for (int j : adj[i]) {
            if (par[i] == j || par[j] == i || i < j) continue;
            auto&& c = extract_cycle(i, j);
            if (cycle[c.size()].empty()) {
                cycle[c.size()] = c;
            } else {
                cout << cycle[c.size()].size() << '\n';
                for (int v: cycle[c.size()]) cout << v + 1 << ' ';
                cout << '\n';
                for (int v: c) cout << v + 1 << ' ';
                cout << '\n';
                return;
            }
        }
    }
}

int main(void) {
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
    file("test");
    // int t; cin >> t; while (t--)
    process();
    return (0^0);
}