#include <bits/stdc++.h>

using namespace std;

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

vector <vector<int>> a;
vector <int> r;
void dfs(int nod)
{
    while(!a[nod].empty())
    {
        int x=a[nod].back();
        a[nod].pop_back();
        auto ind=find(a[x].begin(),a[x].end(),nod);
        if(ind!=a[x].end())
        {
            a[x].erase(ind);
        }
        dfs(x);
    }
    r.push_back(nod);
}
int main()
{
    int n,m;
    in>>n>>m;
    a.resize(n+1);
    for(int i=1;i<=m;i++)
    {
        int x,y;
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    dfs(1);
    for(int i=0;i<m;i++)
    {
        out<<r[i]<<" ";
    }
    return 0;
}