using namespace std;
#include<fstream>
#include<vector>
ifstream eu("sortaret.in");
ofstream tu("sortaret.out");
# define Nmax 100002
vector <int> G[Nmax];
bool use[Nmax];
int N,M,V[Nmax],k;
void DFS(int nod)
{
	vector <int>:: iterator it;
	use[nod]=1;
	for(it=G[nod].begin();it!=G[nod].end();it++)
		if(!use[*it])
			DFS(*it);
	V[++k]=nod;
}
void citire()
{
	int x,y;
	eu>>N>>M;
	for(int i=1;i<=M;i++)
	{
		eu>>x>>y;
		G[x].push_back(y);
		G[y].push_back(x);
	}
}
int main()
{
	citire();
	DFS(1);
	for(int i=k;i>=1;i--)
		tu<<V[i]<<" ";
	return 0;
}