package graphs;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map.Entry;
import java.util.Scanner;

public class Euler {
	

	private Scanner sc;
	private PrintWriter pw;

	private static HashMap<Integer, Integer>[] graph;
	private static ArrayList<Integer> solution;
		
	public Euler() throws FileNotFoundException {
		
		solution = new ArrayList<Integer>();

		pw = new PrintWriter(new File("ciclueuluer.out"));
		
		readData();
				
		parseGraph(0);
		
		for(int v : solution) {
			pw.print((v + 1) + " ");
		}
		
		pw.close();
	}
	
	@SuppressWarnings("unchecked")
	private void readData() {
		try {
			sc = new Scanner(new File("ciclueuluer.in"));
			
			graph = new HashMap[sc.nextInt()];
			
			int vertexes = sc.nextInt();
			
			for (int i = 0; i < vertexes; i++) {
				int vertex1 = sc.nextInt() - 1;
				int vertex2 = sc.nextInt() - 1;
				
				if (graph[vertex1] == null) {
					graph[vertex1] = new HashMap<Integer, Integer>();
				}
				if (graph[vertex2] == null) {
					graph[vertex2] = new HashMap<Integer, Integer>();
				}
								
				if (!graph[vertex1].containsKey(vertex2)) {
					graph[vertex1].put(vertex2, 1);
				} else {
					graph[vertex1].put(vertex2, 2);
				}
				
				if (!graph[vertex2].containsKey(vertex1)) {
					graph[vertex2].put(vertex1, 1);
				} else {
					graph[vertex2].put(vertex1, 2);
				}
				
			}
				
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} finally {
			sc.close();
		}
	}
	
	
	private static void parseGraph(int vertex) {	
		
		System.out.print((vertex + 1) + " ");
		solution.add(vertex);
		
		for(Entry<Integer, Integer> entry : graph[vertex].entrySet()) {
			if (entry.getValue() > 0 && graph[entry.getKey()].getOrDefault(vertex, 0) > 0) {
				entry.setValue(entry.getValue() - 1);
				graph[entry.getKey()].put(vertex, entry.getValue() - 1);
				//System.out.println((vertex + 1) + " - " + (entry.getKey() + 1) + " : " + entry.getValue());
				parseGraph(entry.getKey());
			} 
		};
		
	}
	
	
	public static void main(String args[]) {
		try {
			new Euler();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}
	}

}