#include <fstream>
#include <vector>
using namespace std;
ifstream cin("sortaret.in");
ofstream cout("sortaret.out");
#define MAXN 50005

vector<int> rasp,graf[MAXN];
bool fol[MAXN];
int n,m,i,j,x,y;

void dfs(int nod)
{
    for(int i=0; i<graf[nod].size(); i++)
        if(!fol[ graf[nod][i] ])
        {
            fol[ graf[nod][i] ] = true;
            dfs( graf[nod][i] );
        }
    rasp.push_back(nod);
}

int main()
{
    cin>>n>>m;
    for(i=1; i<=m; i++)
    {
        cin>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    fol[1] = true;
    dfs(1);

    for(i=rasp.size()-1; i>=0; i--)
        cout<<rasp[i]<<" ";
    return 0;

}