#include "worldmap.h"
#include <bits/stdc++.h>
#define FOR(i, a, b) for (auto i = (a); i <= (b); i++)
#define ROF(i, a, b) for (auto i = (a); i >= (b); i--)
using namespace std;
using ll = long long;
int N, t;
vector<bool> vis;
vector<vector<int>> adj, ans;
vector<int> a;
void f(int bagana, int x) {
FOR(i, 0, 4 * N - 1) ans[i][bagana] = x;
}
void dfs(int x, int p) {
vis[x] = 1;
f(t++, x);
vector<int> back;
for (int y : adj[x]) if (vis[y] && y != p) back.push_back(y);
if (!back.empty()) {
int j = 0;
for (int y : back) ans[j++][t] = y, ans[j++][t] = x;
for (; j < 4 * N; j++) ans[j][t] = x;
t++;
f(t++, x);
}
for (int y : adj[x]) {
if (!vis[y]) {
dfs(y, x);
f(t++, x);
}
}
}
std::vector<std::vector<int>> create_map(int _N, int M, std::vector<int> A, std::vector<int> B) {
adj.clear(), vis.clear(), ans.clear(); t = 0;
N = _N; adj.resize(N); vis.resize(N);
ans.resize(4 * N, vector<int>(4 * N));
FOR(i, 0, M - 1) {
A[i]--, B[i]--;
adj[A[i]].push_back(B[i]);
adj[B[i]].push_back(A[i]);
}
dfs(0, -1);
for (; t < 4 * N; t++) f(t, ans[t - 1][0]);
for (auto& x : ans) for (auto& y : x) y++;
return ans;
}
