#include <iostream>
#include <vector>
#include <tuple>
#include <set>
#include <map>
#include <cmath>
#include <string>
#include <algorithm>
#define int long long

using namespace std;

vector <vector <int> > g, comp;
vector <int> used;

void dfs(int v, int color)
{
	if (used[v])
		return;
	used[v] = 1;
	comp[color].push_back(v);
	for (int e : g[v])
		dfs(e, color);
}

signed main()
{
	int n, m;
	cin >> n >> m;

	g.resize(n);
	used.resize(n);

	for (int i = 0; i < m; ++i)
	{
		int u, v;
		cin >> u >> v;
		g[v - 1].push_back(u - 1);
		g[u - 1].push_back(v - 1);
	}

	for (int i = 0; i < n; ++i)
	{
		if (!used[i])
		{
			vector <int> tmp;
			comp.push_back(tmp);
			dfs(i, comp.size() - 1);
		}
	}

	for (auto e1 : comp)
	{
		for (int e : e1)
			cout << e << " ";
		cout << '\n';
	}
}