#include <bits/stdc++.h>
using namespace std;
const int Imx = 2147483647;
const long long Lbig = 2e18;
const int mod = 1e9 + 7;
struct fastio {
  char s[100000];
  int it, len;
  fastio() { it = len = 0; }
  inline char get() {
    if (it < len) return s[it++];
    it = 0;
    len = fread(s, 1, 100000, stdin);
    if (len == 0)
      return EOF;
    else
      return s[it++];
  }
  bool notend() {
    char c = get();
    while (c == ' ' || c == '\n') c = get();
    if (it > 0) it--;
    return c != EOF;
  }
} _buff;
inline long long getnum() {
  long long r = 0;
  bool ng = 0;
  char c;
  c = _buff.get();
  while (c != '-' && (c < '0' || c > '9')) c = _buff.get();
  if (c == '-') ng = 1, c = _buff.get();
  while (c >= '0' && c <= '9') r = r * 10 + c - '0', c = _buff.get();
  return ng ? -r : r;
}
template <class T>
inline void putnum(T x) {
  if (x < 0) putchar('-'), x = -x;
  register short a[20] = {}, sz = 0;
  while (x) a[sz++] = x % 10, x /= 10;
  if (sz == 0) putchar('0');
  for (int i = sz - 1; i >= 0; i--) putchar('0' + a[i]);
}
inline char getreal() {
  char c = _buff.get();
  while (c == ' ' || c == '\n') c = _buff.get();
  return c;
}
int n, m;
int head[200111], nxt[400111], to[400111], tot = 1;
int pe[200111];
bool vis[200111], vise[200111];
vector<pair<int, pair<int, int> > > v;
void dfs(int x, int pv = -1) {
  vis[x] = 1;
  for (int i = head[x]; i; i = nxt[i]) {
    int u = to[i];
    if (!vis[u]) {
      pe[u] = i >> 1;
      dfs(u, x);
    }
  }
  int pre = 0, preid = 0;
  for (int i = head[x]; i; i = nxt[i]) {
    if (vise[i >> 1]) continue;
    if ((i >> 1) == pe[x]) continue;
    if (!pre) {
      pre = to[i];
      preid = i;
    } else {
      v.push_back(make_pair(pre, make_pair(x, to[i])));
      vise[i >> 1] = 1;
      vise[preid >> 1] = 1;
      pre = preid = 0;
    }
  }
  if (pe[x] && pre) {
    v.push_back(make_pair(pv, make_pair(x, pre)));
    vise[pe[x]] = 1;
    vise[preid >> 1] = 1;
  }
}
int main() {
  n = getnum(), m = getnum();
  for (int i = 1; i <= m; i++) {
    int x, y;
    x = getnum(), y = getnum();
    nxt[++tot] = head[x];
    head[x] = tot;
    to[tot] = y;
    nxt[++tot] = head[y];
    head[y] = tot;
    to[tot] = x;
  }
  for (int i = 1; i <= n; i++) {
    if (!vis[i]) {
      dfs(i);
    }
  }
  putnum(v.size()), putchar('\n');
  for (int i = 0; i < v.size(); i++) {
    putnum(v[i].first), putchar(' '), putnum(v[i].second.first), putchar(' '),
        putnum(v[i].second.second), putchar('\n');
  }
  return 0;
}
