#include <bits/stdc++.h>
using namespace std;
//@formatter:off
using ll = long long;
template<typename T> istream &operator>>(istream &is, vector<T> &a);
template<typename T> ostream &operator<<(ostream &os, vector<T> &a);
//@formatter:on
signed main() {
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#else
ios_base::sync_with_stdio(false);
cin.tie(0);
#endif
int n, m;
cin >> n >> m;
vector<vector<int>> g(n);
for (int i = 0; i < m; ++i) {
int u, v;
cin >> u >> v;
g[u - 1].push_back(v - 1);
g[v - 1].push_back(u - 1);
}
vector<int> ord(n);
std::iota(ord.begin(), ord.end(), 0);
std::sort(ord.begin(), ord.end(), [&](int i, int j) {
return g[i].size() > g[j].size();
});
for (int v = 0; v < n; ++v) {
std::sort(g[v].begin(), g[v].end(), [&](int i, int j) {
return g[i].size() < g[j].size();
});
while (!g[v].empty() && g[v].size() < g[g[v].back()].size()) {
g[v].pop_back();
}
}
vector<int> used(n);
for (int u = 0; u < n; ++u) {
int cntl = 0;
used[u] = true;
for (auto v: g[u]) {
cntl++;
used[v] = true;
}
for (auto v: g[u]) {
int cntr = 0;
for (auto v2: g[v]){
if (used[v2]){
cntl--;
} else {
cntr++;
}
}
if (cntl && cntr){
for (auto v2: g[v]){
used[v2] ^= 1;
}
for (auto v2: g[u]){
if (used[v2]){
cout << v2 + 1 << " ";
break;
}
}
for (auto v2: g[v]){
used[v2] ^= 1;
}
cout << u + 1 << " " << v + 1 << " ";
for (auto v2: g[v]){
if (used[v2] == 0){
cout << v2 + 1 << "\n";
break;
}
}
return 0;
}
for (auto v2: g[v]){
if (used[v2]){
cntl++;
} else {
cntr--;
}
}
}
used[u] = false;
for (auto v: g[u]) {
cntl--;
used[v] = false;
}
}
cout << "no" << "\n";
}
// region POZOR
template<typename T>
ostream &operator<<(ostream &os, vector<T> &a) {
for (int i = 0; i < a.size(); i++)
os << a[i] << " \n"[i == a.size() - 1];
return os;
}
template<typename T>
istream &operator>>(istream &is, vector<T> &a) {
for (auto &i: a)
is >> i;
return is;
}
// endregion
