#include <bits/stdc++.h>
using namespace std;
template <class A>
void rd(vector<A>& v);
template <class T>
void rd(T& x) {
  cin >> x;
}
template <class H, class... T>
void rd(H& h, T&... t) {
  rd(h);
  rd(t...);
}
template <class A>
void rd(vector<A>& x) {
  for (auto& a : x) rd(a);
}
template <class T>
bool ckmin(T& a, const T& b) {
  return b < a ? a = b, 1 : 0;
}
template <class T>
bool ckmax(T& a, const T& b) {
  return a < b ? a = b, 1 : 0;
}
template <typename T>
void __p(T a) {
  cout << a;
}
template <typename T, typename F>
void __p(pair<T, F> a) {
  cout << "{";
  __p(a.first);
  cout << ",";
  __p(a.second);
  cout << "}\n";
}
template <typename T>
void __p(std::vector<T> a) {
  cout << "{";
  for (auto it = a.begin(); it < a.end(); it++)
    __p(*it), cout << ",}\n"[it + 1 == a.end()];
}
template <typename T, typename... Arg>
void __p(T a1, Arg... a) {
  __p(a1);
  __p(a...);
}
template <typename Arg1>
void __f(const char* name, Arg1&& arg1) {
  cout << name << " : ";
  __p(arg1);
  cout << "\n";
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args) {
  int64_t bracket = 0, i = 0;
  for (;; i++)
    if (names[i] == ',' && bracket == 0)
      break;
    else if (names[i] == '(')
      bracket++;
    else if (names[i] == ')')
      bracket--;
  const char* comma = names + i;
  cout.write(names, comma - names) << " : ";
  __p(arg1);
  cout << " | ";
  __f(comma + 1, args...);
}
void setIO(string s = "") {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin.exceptions(cin.failbit);
  cout.precision(15);
  cout << fixed;
  if (((int64_t)(s).size())) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
  }
}
signed main() {
  setIO();
  int64_t n, m;
  rd(n, m);
  vector<int64_t> g[n];
  for (int64_t _ = int64_t(0); _ < int64_t(m); ++_) {
    int64_t u, v;
    rd(u, v);
    --u, --v;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  vector<array<int64_t, 3>> ans;
  vector<bool> vis(n, false);
  vector<int64_t> par(n), d(n), down(n, -1);
  for (int64_t k = int64_t(0); k < int64_t(n); ++k)
    if (!vis[k]) {
      function<void(int64_t)> dfs = [&](int64_t i) {
        for (auto j : g[i])
          if (!vis[j]) {
            vis[j] = true;
            par[j] = i;
            d[j] = d[i] + 1;
            dfs(j);
          }
      };
      vis[k] = true;
      par[k] = k;
      d[k] = 0;
      dfs(k);
      function<void(int64_t)> dfs2 = [&](int64_t i) {
        vector<int64_t> now;
        for (auto j : g[i])
          if (d[j] > d[i]) {
            if (d[j] - d[i] > 1) {
              now.push_back(j);
            } else {
              assert(d[j] - d[i] == 1);
              dfs2(j);
              if (down[j] != -1) {
                ans.push_back({i, j, down[j]});
                down[j] = -1;
              } else {
                now.push_back(j);
              }
            }
          }
        if (((int64_t)(now).size()) & 1) {
          down[i] = now.back();
          now.pop_back();
        }
        for (int64_t j = 0; j < ((int64_t)(now).size()); j += 2) {
          ans.push_back({now[j], i, now[j + 1]});
        }
      };
      dfs2(k);
    }
  cout << ((int64_t)(ans).size()) << "\n";
  for (auto e : ans)
    for (int64_t i = int64_t(0); i < int64_t(3); ++i)
      cout << e[i] + 1 << (i == 2 ? '\n' : ' ');
}
