#include<fstream>
#include<vector>


std:: ifstream in ("sortaret.in" );
std:: ofstream out ( "sortaret.out");


const int NMAX= 100005;
int N ,M ,sol[NMAX],vizitat[NMAX],k;
std:: vector <int>L[NMAX];

void citire(){
in>> N >> M ;
for(int i = 0; i<M;i++)
{
    int x , y ;

    in >> x >> y ;

    L[x].push_back(y);
    L[y].push_back(x);
     }
}

void DFS(int nod){
vizitat[nod]=1,sol[++k]=nod;
for(unsigned int i = 0;i<L[nod].size();i++)
    if(vizitat[L[nod][i]]==0)
      DFS(L[nod][i]);

}
int main()
{
    citire();
    DFS(1);
    //out << k << "\n";
    for(int i = 1;i<=k;i++)
     out << sol[i]<<" ";
    return 0 ;
}