#include <fstream>
#include <vector>
using namespace std; 
ifstream cin("sortaret.in");
ofstream cout("sortaret.out");
#define Nmax 100013
 
class cell {
  public : 
 	int node;
 	cell *prev;
 	cell (int a, cell *l) {node=a; prev=l;};
 };
 	  
 class UndirectedGraph {
 	 private : 
 	          cell *adj[Nmax];
 	          bool used[Nmax];
 	          
 	 public : 
	          vector <int> TopSort;
	          int dfs(int node){
 	          	used[node]=1;
 	          	for (cell *it = adj[node];it;it=it->prev)
 	          	   if (!used[it->node])
 	          	     dfs(it->node);
       	         TopSort.push_back(node);
          	     return 1;
 	          	 }
 	          	 
 		      void addEdge(int a,int b){
 		      	 cell *aux = new cell(b,adj[a]); adj[a]=aux;
 		      	       aux = new cell(a,adj[b]); adj[b]=aux;
 		      }
 } Graph;
 
int n,m,a,b;
int main(void) {
 cin>>n>>m;
 while(m--) {
 	cin>>a>>b;
 	Graph.addEdge(a,b);
    }
 Graph.dfs(1);
 vector <int>::iterator it;
 for (it=Graph.TopSort.end()-1;it!=Graph.TopSort.begin()-1;--it)
     cout<<*it<<" ";
 return 0;
}