#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;
ifstream fin("ciclueuler.in");
ofstream fout("ciclueuler.out");

vector<int> v[100005], sol;
int n, m, x, y;

void euler(int nod){
    for(int i = 0; i < v[nod].size(); ++i){
        int nxt = v[nod][i];
        v[nod].erase(v[nod].begin() + i);
        v[nxt].erase( find(v[nxt].begin(), v[nxt].end(), nod) );
        euler(nxt);
    }
    sol.push_back(nod);
}
int main()
{
    fin >> n >> m;
    for(int i = 1; i <= m; ++i){
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    euler(1);
    for(vector<int>::reverse_iterator it = sol.rbegin(); it != sol.rend() - 1; ++it)
        fout << *it << ' ';
    return 0;
}