#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<double> vd;
typedef vector<bool> vb;
typedef vector<char> vc;
typedef vector<string> vs;
typedef vector<pi> vp;
typedef vector<pl> vpl;
const int maxn = 1010;
int n, m;
bool ok = 0;
vi e[maxn], vis(maxn);
stack<int> s;
void solve(){
while(!s.empty()){
cout << s.top() << ' ';
s.pop();
}
cout << '\n';
exit(0);
}
vi ud(maxn, 0);
void dfs(int x, int c, int st){
vis[x]++;
s.push(x);
//cout << "USO " << x << ' ' << c << endl;
for (auto& i : e[x]){
if (i == st){
if (c >= 4) solve();
continue;
}
if (vis[i] || (ud[i] && c < 3)){
++vis[i];
continue;
}
++vis[i];
dfs(i, c + 1, st);
}
for (auto& i : e[x])
if (i != st)
--vis[i];
--vis[x];
//cout << "IZASO " << x << '\n';
s.pop();
}
void init(){
for (int i = 1; i <= n; ++i){
vis[i] = 0;
}
while(!s.empty()) s.pop();
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
cerr.tie(nullptr);
cin >> n >> m;
for (int i = 0; i < m; ++i){
int u, v;
cin >> u >> v;
e[u].push_back(v);
e[v].push_back(u);
}
for (int i = 1; i <= n; ++i){
init();
//if (i != 2) continue;
s.push(i);
for (auto& j : e[i])
ud[j] = 1;
for (auto& j : e[i]){
dfs(j,2,i);
}
}
cout << "no\n";
}
