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

#define rep(i, n) for (int i = 0; i < (int)(n); i++)

const int N = 10000 + 7;

int n, m;
vector<pair<int, int>> adj[N];
vector<int> tree[N];
int sz[N], vis[N];
int par[N], color[N];
int edge[N];
bool is_tree[N];
pair<int, int> edges[N];

void dfs(int u) {
	vis[u] = true;
	sz[u] = 1;
	for (auto [v, i] : adj[u]) {
		if (!vis[v]) {
			edge[v] = i;
			is_tree[i] = true;
			par[v] = u;
			dfs(v);
			sz[u] += sz[v];
			tree[u].push_back(v);
		}
	}
}

int pre[N], czas;
void hld(int u, int col) {
	sort(tree[u].begin(), tree[u].end(),
		[&](int a, int b) {
			return sz[a] > sz[b];
		}
	);

	pre[u] = czas++;
	color[edge[u]] = col;

	int now = 1;
	for (int v : tree[u]) {
		if (now == col)
			now++;

		hld(v, now);
		now++;
	}
}

vector<int> to_root[N];

int jmp[N];
int ori[N];
int idx[N];

void dfs2(int u) {
	if (u != 1) {
		to_root[u] = to_root[par[u]];
		to_root[u].push_back(color[edge[u]]);
	}
	
	jmp[u] = u;
	ori[u] = -1;
	idx[u] = -1;
	for (auto [v, i] : adj[u]) {
		if (!is_tree[i] && pre[jmp[u]] > pre[v]) {
			jmp[u] = v;
			ori[u] = u;
			idx[u] = i;
		}
	}

	for (int v : tree[u]) {
		dfs2(v);

		if (pre[jmp[u]] > pre[jmp[v]]) {
			jmp[u] = jmp[v];
			ori[u] = ori[v];
			idx[u] = idx[v];
		}
	}
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	cin >> n >> m;
	rep(i, m) {
		int u, v;
		cin >> u >> v;
		adj[u].emplace_back(v, i + 1);
		adj[v].emplace_back(u, i + 1);
		edges[i + 1] = make_pair(u, v);
	}

	dfs(1);
	hld(1, -1);

	int col = *max_element(color + 1, color + 1 + m);
	
	for (int i = 1; i <= m; i++) {
		if (color[i] == 0) {
			color[i] = ++col;
		}

		cout << color[i] << ' ';
	}
	cout << '\n';

	dfs2(1);

	for (int i = 1; i <= m; i++) {
		if (is_tree[i]) {
			auto [u, v] = edges[i];
			if (pre[u] > pre[v])
				swap(u, v);

			set<int> S;

			S.insert(color[idx[v]]);

			for (int x : to_root[ori[v]])
				S.insert(x);

			for (int x : to_root[u])
				S.insert(x);

			cout << S.size() << ' ';
			for (int x : S)
				cout << x << ' ';
			cout << '\n';
		}
		else {
			auto [u, v] = edges[i];
			
			set<int> S;
			for (int x : to_root[u])
				S.insert(x);

			for (int x : to_root[v])
				S.insert(x);

			cout << S.size() << ' ';
			for (int x : S)
				cout << x << ' ';
			cout << '\n';
		}
	}
}