#include <fstream>
#include<vector>
using namespace std;
ifstream f("sortaret.in");
ofstream g("sortaret.out");
vector<int> v[50001];
int n,m,x,y,i, a[50001],viz[50001],k;
void df(int x){
   viz[x]=1;
   for(int i=0;i<v[x].size();i++)
      if(viz[v[x][i]]==0)
          df(v[x][i]);
  a[++k]=x;

}
int main()
{
    f>>n>>m;
    for(i=1;i<=m;i++){
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
df(1);
for(i=k;i>=1;i--)
    g<<a[i]<<" ";
    return 0;
}