#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2e5 + 7;
struct Kek {
  int a, b, c;
};
int n, m;
vector<int> g[MAXN];
vector<Kek> ans;
void read() {
  cin >> n >> m;
  for (int i = 0; i < m; ++i) {
    int u, v;
    cin >> u >> v;
    --u;
    --v;
    g[u].push_back(v);
    g[v].push_back(u);
  }
}
bool used[MAXN];
int par[MAXN];
bool us[MAXN];
int h[MAXN];
void dfs(int u, int parent, int d) {
  h[u] = d;
  par[u] = parent;
  used[u] = 1;
  for (int v : g[u]) {
    if (!used[v]) {
      dfs(v, u, d + 1);
    }
  }
  vector<int> a;
  for (int v : g[u]) {
    if (h[v] < h[u]) {
      continue;
    } else if (par[v] == u) {
      if (!us[v]) {
        a.push_back(v);
      }
    } else {
      a.push_back(v);
    }
  }
  if (a.size() % 2 == 0) {
    for (int i = 0; i < (int)a.size(); i += 2) {
      ans.push_back({a[i], u, a[i + 1]});
    }
  } else {
    for (int i = 0; i < (int)a.size() - 1; i += 2) {
      ans.push_back({a[i], u, a[i + 1]});
    }
    if (parent != -1) {
      us[u] = 1;
      ans.push_back({a.back(), u, parent});
    }
  }
}
void solve() {
  for (int i = 0; i < n; ++i) {
    if (!used[i]) {
      dfs(i, -1, 0);
    }
  }
}
void print() {
  cout << ans.size() << '\n';
  for (auto e : ans) {
    cout << e.a + 1 << ' ' << e.b + 1 << ' ' << e.c + 1 << '\n';
  }
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  read();
  solve();
  print();
  return 0;
}
