#include <bits/stdc++.h>

using namespace std;

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

int n,i,a,b,m,vecin;
vector <int> v[100005];
vector <int> sol;

int DFS(int start){
    for(int i=0;i<v[start].size();i++){
        if(v[start][i]){
        vecin = v[start][i];
        v[start][i] = 0;
        for(int j=0;j<v[vecin].size();j++){
            if(v[vecin][j] == start){
                v[vecin][j] = 0;
                break;
            }
        }
        DFS(vecin);
        }
    }
    sol.push_back(start);
}



int main()
{
fin>>n>>m;
while(m--){
    fin>>a>>b;
    v[a].push_back(b);
    v[b].push_back(a);;
}
DFS(1);
for(i=0;i<sol.size();i++){
    fout << sol[i] << " ";
}

    return 0;
}