#include <bits/stdc++.h>

using namespace std;

ifstream fin("ciclueuler.in");
ofstream fout("ciclueuler.out");

vector<vector<int>> G;
vector<int> ciclu;
int i, x, y, n, m;
void cicluEulerian(int nod)
{
    //cout<<nod;
    for(;G[nod].size();)
    {
        auto it = G[nod].back();
        G[nod].erase(find(G[nod].begin(), G[nod].end(), it));
        G[it].erase(find(G[it].begin(), G[it].end(), nod));
        cicluEulerian(it);
    }
    ciclu.push_back(nod);
}
int main()
{
    fin>>n>>m;
    G.resize(n+1);
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    cicluEulerian(1);
    ciclu.pop_back();
    for(const auto& it : ciclu)
        fout<<it<<" ";
    return 0;
}