#include <bits/stdc++.h>
using namespace std;
ifstream fin("ciclueuler.in");
ofstream fout("ciclueuler.out");
#define MAXN 100005

int n,m;
unordered_multiset<int> G[MAXN];
vector<int> ciclu;

void dfs(int node){
    while(!G[node].empty()){
        auto it1 = G[node].begin();
        int vec = *it1;
        G[node].erase(it1);

        auto it2 = G[vec].find(node);
        G[vec].erase(it2);

        dfs(vec);
    }
    ciclu.push_back(node);
}

int main()
{
    int x, y;
    fin>>n>>m;
    while(m--){
        fin>>x>>y;
        G[x].insert(y);
        G[y].insert(x);
    }
    dfs(1);
    ciclu.pop_back();
    for(auto p : ciclu)
        fout<<p<<" ";
	return 0;
}