#include <bits/stdc++.h>

using namespace std;

#define rep(i, s, e) for (int i = s; i <= e; ++i)
#define per(i, s, e) for (int i = s; i >= e; --i)
#define file(a) freopen(#a".in", "r", stdin), freopen(#a".out", "w", stdout)
#define pv(a) cout << #a << " = " << a << endl
#define pa(a, l, r) cout << #a " : "; rep(_, l, r) cout << a[_] << " \n"[_ == r]

const int N = 1e3 + 10;

int read() {
  int x = 0, f = 1; char c = getchar();
  for (; c < '0' || c > '9'; c = getchar()) if (c == '-') f = -1;
  for (; c >= '0' && c <= '9'; c = getchar()) x = x * 10 + (c - 48);
  return x * f;
}

int n;
vector <tuple <int, int, int>> ans;

void f(int i, int j, int k) {
  assert(i != j && i != k && j != k);
  if (i > j) swap(i, j);
  if (j > k) swap(j, k);
  if (i > j) swap(i, j);
  ans.emplace_back(make_tuple(i, j, k));
}

int main() {
  n = read();
  if (n & 1) {
    rep(i, 1, n) rep(d, 1, (n - 1) / 2) {
      int j = (i - d - 1 + n) % n + 1;
      int k = (i + d - 1) % n + 1;
      f(i, j, k);
    }
  }
  else {
    --n;
    rep(i, 1, n) rep(d, 1, (n - 1) / 2) {
      int j = (i - d - 1 + n) % n + 1;
      int k = (i + d - 1) % n + 1;
      f(i, j, k);
      if (d > 1) f(i, j, k);
    }
    ++n;
    rep(i, 1, n - 1) {
      f(n, i, i % (n - 1) + 1);
      f(n, i, i % (n - 1) + 1);
      f(n, i, (i + 1) % (n - 1) + 1);
    }
  }
  printf("%d\n", (int) ans.size());
  for (auto [i, j, k] : ans) {
    printf("%d %d %d\n", i, j, k);
  }
  return 0;
}