#include<stdio.h>
#include<vector>
#define Nmx 100005

using namespace std;

int n,m,grd[Nmx],s[Nmx*5],nr;
vector<int> G[Nmx];

void citire()
{
    scanf("%d%d",&n,&m);
    int x,y;
    for(int i=1;i<=m;++i)
    {
        scanf("%d%d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
        grd[x]++;
        grd[y]++;
    }
}

void solve()
{
    s[++nr]=1;
    while(nr)
    {
        int nod=s[nr];
        if(!G[nod].empty())
        {
            int x=G[nod].back();
            G[nod].pop_back();
            s[++nr]=x;
            vector<int> :: iterator it;
            for(it=G[x].begin() ; it!=G[x].end() && *it!=nod ;it++);
               G[x].erase(it);
        }
        else printf("%d ",s[nr--]);
    }
}

int main()
{
    freopen("ciclueuler.in","r",stdin);
    freopen("ciclueuler.out","w",stdout);
    citire();
    solve();
    return 0;
}