#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using Pii = pair<int, int>;
using Pll = pair<ll, ll>;
template <typename...>
static inline int getchar_unlocked(void) {
  return getchar();
}
template <typename...>
static inline void putchar_unlocked(int c) {
  putchar(c);
}
void reader(int& x) {
  int k, m = 0;
  x = 0;
  for (;;) {
    (k) = getchar_unlocked();
    if (k == '-') {
      m = 1;
      break;
    }
    if ('0' <= k && k <= '9') {
      x = k - '0';
      break;
    }
  }
  for (;;) {
    (k) = getchar_unlocked();
    if (k < '0' || k > '9') break;
    x = x * 10 + k - '0';
  }
  if (m) x = -x;
}
void reader(ll& x) {
  int k, m = 0;
  x = 0;
  for (;;) {
    (k) = getchar_unlocked();
    if (k == '-') {
      m = 1;
      break;
    }
    if ('0' <= k && k <= '9') {
      x = k - '0';
      break;
    }
  }
  for (;;) {
    (k) = getchar_unlocked();
    if (k < '0' || k > '9') break;
    x = x * 10 + k - '0';
  }
  if (m) x = -x;
}
int reader(char c[]) {
  int i, s = 0;
  for (;;) {
    (i) = getchar_unlocked();
    if (i != ' ' && i != '\n' && i != '\r' && i != '\t' && i != EOF) break;
  }
  c[s++] = i;
  for (;;) {
    (i) = getchar_unlocked();
    if (i == ' ' || i == '\n' || i == '\r' || i == '\t' || i == EOF) break;
    c[s++] = i;
  }
  c[s] = '\0';
  return s;
}
int reader(string& c) {
  int i;
  for (;;) {
    (i) = getchar_unlocked();
    if (i != ' ' && i != '\n' && i != '\r' && i != '\t' && i != EOF) break;
  }
  c.push_back(i);
  for (;;) {
    (i) = getchar_unlocked();
    if (i == ' ' || i == '\n' || i == '\r' || i == '\t' || i == EOF) break;
    c.push_back(i);
  };
  return ((int)c.size());
}
template <class T, class S>
void reader(T& x, S& y) {
  reader(x);
  reader(y);
}
template <class T, class S, class U>
void reader(T& x, S& y, U& z) {
  reader(x);
  reader(y);
  reader(z);
}
template <class T, class S, class U, class V>
void reader(T& x, S& y, U& z, V& w) {
  reader(x);
  reader(y);
  reader(z);
  reader(w);
}
void writer(int x, char c) {
  int s = 0, m = 0;
  char f[10];
  if (x < 0) m = 1, x = -x;
  while (x) f[s++] = x % 10, x /= 10;
  if (!s) f[s++] = 0;
  if (m) putchar_unlocked('-');
  while (s--) putchar_unlocked(f[s] + '0');
  putchar_unlocked(c);
}
void writer(ll x, char c) {
  int s = 0, m = 0;
  char f[20];
  if (x < 0) m = 1, x = -x;
  while (x) f[s++] = x % 10, x /= 10;
  if (!s) f[s++] = 0;
  if (m) putchar_unlocked('-');
  while (s--) putchar_unlocked(f[s] + '0');
  putchar_unlocked(c);
}
void writer(const char c[]) {
  int i;
  for (i = 0; c[i] != '\0'; i++) putchar_unlocked(c[i]);
}
void writer(const string& x, char c) {
  int i;
  for (i = 0; x[i] != '\0'; i++) putchar_unlocked(x[i]);
  putchar_unlocked(c);
}
void writer(const char x[], char c) {
  int i;
  for (i = 0; x[i] != '\0'; i++) putchar_unlocked(x[i]);
  putchar_unlocked(c);
}
template <class T>
void writerLn(T x) {
  writer(x, '\n');
}
template <class T, class S>
void writerLn(T x, S y) {
  writer(x, ' ');
  writer(y, '\n');
}
template <class T, class S, class U>
void writerLn(T x, S y, U z) {
  writer(x, ' ');
  writer(y, ' ');
  writer(z, '\n');
}
template <class T>
void writerArr(T x[], int n) {
  if (!n) {
    putchar_unlocked('\n');
    return;
  }
  for (int i = 0; i < (n - 1); i++) writer(x[i], ' ');
  writer(x[n - 1], '\n');
}
template <class T>
void writerArr(vector<T>& x) {
  writerArr(x.data(), (int)x.size());
}
template <class T>
void chmin(T& a, const T& b) {
  if (a > b) a = b;
}
template <class T>
void chmax(T& a, const T& b) {
  if (a < b) a = b;
}
template <class T>
T gcd(T a, T b) {
  return b ? gcd(b, a % b) : a;
}
template <class T>
T lcm(T a, T b) {
  return a / gcd(a, b) * b;
}
ll mod_pow(ll a, ll n, ll mod) {
  ll ret = 1;
  ll p = a % mod;
  while (n) {
    if (n & 1) ret = ret * p % mod;
    p = p * p % mod;
    n >>= 1;
  }
  return ret;
}
template <class T>
T extgcd(T a, T b, T& x, T& y) {
  for (T u = y = 1, v = x = 0; a;) {
    T q = b / a;
    swap(x -= q * u, u);
    swap(y -= q * v, v);
    swap(b -= q * a, a);
  }
  return b;
}
template <class T>
T mod_inv(T a, T m) {
  T x, y;
  extgcd(a, m, x, y);
  return (m + x % m) % m;
}
class UnionFind {
 private:
  int n;
  vector<int> a;

 public:
  UnionFind(int n) : n(n), a(n, -1) {}
  int find(int x) { return a[x] < 0 ? x : (a[x] = find(a[x])); }
  bool same(int x, int y) { return find(x) == find(y); }
  bool same(Pii& p) { return same(p.first, p.second); }
  bool unite(int x, int y) {
    x = find(x), y = find(y);
    if (x == y) return false;
    if (a[x] > a[y]) swap(x, y);
    a[x] += a[y];
    a[y] = x;
    n--;
    return true;
  }
  bool unite(Pii& p) { return unite(p.first, p.second); }
  int size() const { return n; }
  int size(int x) { return -a[find(x)]; }
};
vector<int> e[((int)1e5) * 2];
set<int> rem[((int)1e5) * 2];
vector<tuple<int, int, int>> anses;
bool dfs(int v, int par) {
  int etc = -1;
  if (((int)rem[v].size())) {
    auto it = rem[v].begin();
    int a = *it;
    rem[v].erase(it);
    rem[a].erase(v);
    etc = a;
  }
  for (auto to : e[v]) {
    if (to == par) continue;
    bool used = dfs(to, v);
    if (!used) {
      if (etc == -1) {
        etc = to;
      } else {
        anses.emplace_back(etc, v, to);
        etc = -1;
      }
    }
  }
  if (etc != -1) {
    if (par != -1) anses.emplace_back(etc, v, par);
    return true;
  } else {
    return false;
  }
}
int main() {
  int n, m;
  reader(n, m);
  UnionFind uf(n);
  for (int i = 0; i < (m); i++) {
    int a, b;
    reader(a, b);
    a--;
    b--;
    if (uf.unite(a, b)) {
      e[a].push_back(b);
      e[b].push_back(a);
    } else {
      rem[a].insert(b);
      rem[b].insert(a);
    }
  }
  for (int i = 0; i < (n); i++) {
    auto& s = rem[i];
    while (((int)s.size()) >= 2) {
      auto it = s.begin();
      int a = *it;
      s.erase(it);
      it = s.begin();
      int b = *it;
      s.erase(it);
      anses.emplace_back(a, i, b);
      rem[a].erase(i);
      rem[b].erase(i);
    }
  }
  for (int i = 0; i < (n); i++) {
    if (uf.find(i) == i) {
      dfs(i, -1);
    }
  }
  writerLn(((int)anses.size()));
  for (auto& abc : anses) {
    int a, b, c;
    tie(a, b, c) = abc;
    writerLn(a + 1, b + 1, c + 1);
  }
  return 0;
}
