#include <fstream>
#include <vector>
#include <stack>
#include <algorithm>
using namespace std;
ifstream cin("ciclueuler.in");
ofstream cout("ciclueuler.out");
int n,m,i,j,x,y,nod,next;
vector<int> graf[100001];
stack<int> st;
int main()
{
    cin>>n>>m;
    for(i=1; i<=m; i++)
    {
        cin>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }

    st.push(1);
    while(!st.empty())
    {
        nod=st.top();
        if(!graf[nod].size())
        {
            cout<<nod<<" ";
            st.pop();
        }
        else
        {
            next=graf[nod].back();
            st.push(next);

            graf[nod].pop_back();
            graf[next].erase(find(graf[next].begin(),graf[next].end(),nod));
        }
    }
}