#include <bits/stdc++.h>

using namespace std;

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

const int nmax = 100005;

int n, m;

vector < int > l[nmax];

vector < int > v;

bitset < nmax > viz[nmax];

void Dfs(int nod)
{
    for (int next : l[nod])
    {
        if (!viz[nod][next])
        {
            viz[nod][next] = viz[next][nod] = 1;
            Dfs(next);
        }
    }

    v.push_back(nod);
}

int main()
{
    fin >> n >> m;

    for (int i = 1; i <= m; i++)
    {
        int a, b;

        fin >> a >> b;

        l[a].push_back(b);
        l[b].push_back(a);
    }

    Dfs(1);

    for (int i = 0; i < v.size() - 1; i++)
        fout << v[i] << ' ';

    fin.close();
    fout.close();
    return 0;
}