#include <fstream>
#include <queue>
#include <bitset>
using namespace std;
ifstream fin("ciclueuler.in");
ofstream fout("ciclueuler.out");
int i,n,m,ok,nr,nod,vecin;
int a[500001],b[500001],d[500001];
vector<int> v[100001],q;
vector<int>::iterator it;

int main()
{
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>a[i]>>b[i];
        v[a[i]].push_back(i);
        v[b[i]].push_back(i);
    }
    q.push_back(1);
    while(!q.empty())
    {
        nod=q.back();nr=0;
        for(it=v[nod].begin();it!=v[nod].end();it++)
        {
            vecin=a[*it]+b[*it]-nod;
            if(d[*it]==0)
            {
                nr++;
                d[*it]=1;
                q.push_back(vecin);
                break;
            }
        }
        if(nr==0)
        {
            if(ok==1) fout<<nod<<" ";
            ok=1;q.pop_back();
        }
    }
    fin.close();
    fout.close();
    return 0;
}