import java.util.*;
import java.io.*;

public class DepthTraverse {
	int[][] arr;
	public DepthTraverse(String fn){
		populate(fn);
	}
	
	private void populate(String str) {
		try{
		//assuming the str is the name of the file
		Scanner s = new Scanner( new File(str) );		
		int n = s.nextInt();
		int m = s.nextInt();
		arr = new int[n][n];
		while(s.hasNext()){
			int f = s.nextInt() - 1;
			int t = s.nextInt() -1 ;
			arr[f][t] = 1;
			arr[t][f] = 1;
		}
		}catch(Exception ex){}
	}
	public void printPath(){
		int src = 0;
		System.out.print(1);
		for(int i=0;i<arr.length-1;i++){
			int smallest = findSmallest(arr[src]);
			//update the array
			arr[smallest][src] = 0;
			for(int j=0;j<arr.length;j++){
				arr[j][src] = 0;				
			}
			System.out.print( " " + (smallest+1));
			src = smallest;
		}
		System.out.println();
	}	
	
	
	
	
	public int findSmallest(int[] arr){
		for(int i=0;i<arr.length;i++)
			if(arr[i] != 0) return i;
		return -1;
	}

	public static void main(String[] args){
		String fn = "input.c");
		DepthTraverse dt2 = new DepthTraverse(fn);
		dt2.printPath();				
	}
	
}