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

#define SZ(a) (int)a.size()
#define ALL(a) a.begin(), a.end()
#define FOR(i, a, b) for (int i = (a); i<(b); ++i)
#define RFOR(i, b, a) for (int i = (b)-1; i>=(a); --i)
#define MP make_pair
#define PB push_back
#define F first
#define S second

typedef long long LL;
typedef pair<int, int> PII;
typedef vector<int> VI;

const int N = 300'447;
VI g[N];
VI g2[N];
int s[N];
bool used[N];
set<int> all;
set<PII> cmp;
int lef;

int dfs1(int v)
{
	used[v] = 1;
	s[v] = 1;
	for (auto to : g[v])
	{
		if (!used[to])
		{
			s[v] += dfs1(to);
			g2[v].PB(to);
		}
	}
	return s[v];
}

int dfs2(int v)
{
	all.erase(v);
	auto it = all.begin();
	s[v] = 1;
	FOR (i, 0, SZ(g[v]))
	{
		if (it == all.end()) return s[v];
		auto to = g[v][i];
		if (to < *it) continue;
		if (to == *it)
		{
			it++;
			continue;
		}
		to = *it;
		s[v] += dfs2(to);
		g2[v].PB(to);
		it = all.lower_bound(to);
	}
	while(it != all.end()){
		int	to = *it;
		//cerr << v << ": " << to << endl;
		
		s[v] += dfs2(to);
		g2[v].PB(to);
		it = all.lower_bound(to);
	}

	return s[v];
}

void restore(int v)
{
	cout << v + 1 << ' ';
	cmp.erase({s[v], v});
	int tot = -1;
	if(!cmp.empty())
		tot = cmp.rbegin()->second;
	for (auto to : g2[v])
	{
		cmp.insert({s[to], to});
	}	
	if(tot != -1)
		restore(tot);
}

void dfs3(int v)
{
	cout << v + 1 << ' ';
	lef--;
	cmp.erase({s[v], v});
	int mxOld = (cmp.empty() ? -1 : cmp.rbegin()->second);
	
	
	for (auto to : g2[v])
	{
		cmp.insert({s[to], to});
	}	
	
	if(mxOld != -1 && (cmp.rbegin()->first * 2 < lef + 1 || s[mxOld] == cmp.rbegin()->first)){
		restore(mxOld);
		cout << endl;
		exit(0);
	}
	
	 
	sort(ALL(g2[v]), [&](int a, int b)
	{
		return s[a] > s[b];
	});
	if(!g2[v].empty())
		dfs3(g2[v][0]);
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n, m;
	cin >> n >> m;
	lef = n;
	
	FOR (i, 0, m)
	{
		int a, b;
		cin >> a >> b;
		a--, b--;
		g[a].PB(b);
		g[b].PB(a);
	}
	int sz = dfs1(0);
	if (sz != n)
	{
		FOR (i, 0, n) 
		{
			s[i] = 0;
			g2[i].clear();
			sort(ALL(g[i]));
			used[i] = false;
			all.insert(i);
		}
		dfs2(0);
		/*FOR(i, 0, n){
			for(int to : g2[i])
				cout << to << " ";
			cout << endl;
		}*/
	}
	dfs3(0);
	cout << endl;
	assert(lef == 0);
	
	return 0;
}