#include <bits/stdc++.h>
const int N = 2e5 + 5;
std::multiset <int> v[N];
std::vector <int> t[N], ans;
std::vector <std::pair <int, int> > g[N];
int n, m, tis[N];
void addedge(int x, int y) {
	v[x].insert(y);
	v[y].insert(x);
}
bool vis[N];
int ID;
bool FLG;
void dfs(int p) {
	vis[p] = true;
	std::vector <int> tmp;
	for (int u : v[p]) {
		if (!vis[u]) {
			tis[u] ++;
			dfs(u);
			FLG = true;
			g[ID].push_back(std::make_pair(p, u));
			tmp.push_back(u);
		}
	}
	for (int u : tmp) {
		v[u].erase(v[u].find(p));
		v[p].erase(v[p].find(u));
	}
}
void buildt(int id) {
	for (auto u : g[id]) {
		t[u.first].push_back(u.second);
		t[u.second].push_back(u.first);
	}
}
void dfst(int p, int en) {
	ans.push_back(p);
	if (p == en) return;
	vis[p] = true;
	for (int u : t[p]) {
		if (!vis[u]) dfst(u, en);
		if (ans.back() == en) return;
	}
	if (ans.back() == en) return; 
	vis[p] = false;
	ans.pop_back();
	return;
}
void solve() {
	int k = m / (n - 1) + ((m % (n - 1) == 0) ? 0 : 1);
	for (ID = 1; ID <= k - 1; ID ++) {
		for (int i = 1; i <= n; i ++) vis[i] = 0;
		for (int i = 1; i <= n; i ++) {
			if (!vis[i]) {
				FLG = false;
				dfs(i);
				tis[i] += FLG;
			}
		}
	}
	int st = 0, fn = 0;
	for (int i = 1; i <= n; i ++) {
		for (int u : v[i]) {
			if (tis[i] == k - 1 && tis[u] == k - 1) {
				st = i; fn = u;
				break;
			}
		}
		if (st) break;
	}
	std::cout << st << ' ' << fn << '\n';
	for (int i = 1; i <= k - 1; i ++) {
		ans.clear();
		for (int j = 1; j <= n; j ++) {
			t[j].clear();
			vis[j] = 0;
		}
		buildt(i);
		dfst(st, fn);
		std::cout << ans.size() << ' ';
		for (int j = 0; j + 1 < ans.size(); j ++) {
			std::cout << ans[j] << ' ';
		}
		std::cout << ans.back() << '\n';
	}
	std::cout << 2 << ' ' << st << ' ' << fn << '\n';
	for (int i = 1; i <= k - 1; i ++) g[i].clear();
}
int main() {
	std::ios::sync_with_stdio(false);
	int T;
	std::cin >> T;
	while (T --) {
		int x, y;
		std::cin >> n >> m;
		for (int i = 1; i <= m; i ++) {
			std::cin >> x >> y;
			addedge(x, y);
		}
		solve();
		for (int i = 1; i <= n; i ++) v[i].clear(), tis[i] = 0;
	}
	return 0;
}