#include <bits/stdc++.h>
using namespace std;
vector<long long> v[10001];
long long n, ass1, ass2;
int main() {
  v[1].push_back(1);
  v[1].push_back(2);
  v[2].push_back(1);
  v[2].push_back(3);
  v[3].push_back(2);
  v[3].push_back(3);
  cin >> n;
  ass1 = ass2 = 3;
  while (ass1 + ass2 <= n) {
    v[1].push_back(ass2 + 1);
    v[ass1 + 1].push_back(ass2 + 1);
    for (int i = 2; i <= ass1; i++) {
      v[i].push_back(ass2 + i);
      v[ass1 + 1].push_back(ass2 + i);
    }
    ass2 += ass1;
    ass1++;
  }
  cout << ass1 << endl;
  for (int i = 1; i <= ass1; i++) {
    for (int j = 0; j < v[i].size(); j++) {
      if (j != 0) cout << ' ';
      cout << v[i][j];
    }
    cout << endl;
  }
  return 0;
}
