#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> ii;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ii> vii;
typedef vector<vii> wgraf;
typedef pair<int,ii> edge;
typedef vector <ll> vl;
typedef pair <ll, ll> LL;
typedef vector <LL> vll;
#define UNVISITED 0
#define VISITED 1
#define pb push_back
#define F first
#define S second
ll n, m, u, v;
vll grafo[500005];
map <ll, ll> sale;
map <ll, bool> puede;
bool visto[500005], vale = false;
void dfs(ll origen, ll nodo, ll padre) {
sale[nodo]--;
if (nodo == origen && padre != -1) {
vale = true;
return;
}
for (auto i : grafo[nodo]) {
if (i.F != padre && puede[i.S] == true && visto[i.F] == false) {
puede[i.S] = false;
visto[i.F] = true;
dfs(origen, i.F, nodo);
puede[i.S] = true;
visto[i.F] = false;
}
if (vale == true) {
if (nodo != origen) cout << nodo << " ";
else cout << nodo << "\n";
sale[i.F]--;
puede[i.S] = false;
return;
}
}
}
/*
4 10
1 2
2 3
3 4
4 1
5 6
6 7
7 8
8 5
2 5
8 3
*/
void SOLVE(){
cin >> n >> m;
for (ll i = 0; i < n; i++) visto[i] = false;
for (ll i = 0; i < m; i++){
cin >> u >> v;
grafo[u].pb({v, i});
grafo[v].pb({u, i});
sale[u]++;
sale[v]++;
puede[i] = true;
}
for (auto i : sale) {
if(i.S > 0) {
vale = false;
dfs(i.F, i.F, -1);
i.S--;
}
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t = 1;
//cin >> t;
while(t--){
SOLVE();
}
}
