using namespace std;
#include<fstream>
#include<vector>
#define Nmax 100005
ifstream fin("sortaret.in");
ofstream fout("sortaret.out");
vector<int> G[Nmax];
bool use[Nmax];int N,M,O[Nmax],k;
void Read()
{
fin>>N>>M;
for( int i=1;i<=M;i++)
	{
	int x,y;
	fin>>x>>y;
	G[x].push_back(y);
	G[y].push_back(x);
	}
}
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);
	O[++k]=nod;
}
int main()
{
	Read();
	DFS(1);
	for(int i=k;i>=1;i--)
			fout<<O[i]<<" ";
	return 0;
}