#include <iostream>
#include <fstream>
#include <vector>
#include <stack>
#include <queue>
#include <conio.h>

using namespace std;

int n, m;
vector<vector<int> > graph;
vector<bool> visited;
queue<int> solutie;

ifstream f("sortaret.in");
ofstream g("sortaret.out");

void dfs(int vertex)
{
	if (vertex<0 || vertex>n - 1)
		return;
	stack<int> s;
	unsigned int element, i;
	bool found;
	s.push(vertex);
	visited[vertex] = true;
	solutie.push(vertex);
	while (!s.empty())
	{
		element = s.top();
		found = false;
		for (i = 0; i<graph[element].size() && !found; i++)
			if (!visited[graph[element][i]])
				found = true;
		if (found)
		{
			i--;
			s.push(graph[element][i]);
			solutie.push(graph[element][i]);
			visited[graph[element][i]] = true;
		}
		else
			s.pop();
	}
}

int main()
{
	f >> n >> m;
	graph.resize(n);
	visited.resize(n, false);
	int x, y, i, c = 0;
	for (i = 0; i<m; i++)
	{
		f >> x >> y;
		x--;
		y--;
		graph[x].push_back(y);
		graph[y].push_back(x);
	}
	for (i = 0; i<visited.size() && i<n; i++)
		if (!visited[i])
			dfs(i);
	cout << endl;
	for (i = 0; i < n; i++)
	{
		g << solutie.front()+1 << " ";
		solutie.pop();
	}
	_getch();
	f.close();
	g.close();
	return 0;
}