#include <bits/stdc++.h>
using namespace std;
#include <atcoder/modint>
using namespace atcoder;
//using mint = modint998244353;
using mint = modint1000000007;
using ll = long long;
using ld = long double;
using pll = pair<ll, ll>;
using tlll = tuple<ll, ll, ll>;
constexpr ll INF = 1LL << 60;
template<class T> bool chmin(T& a, T b) {if (a > b) {a = b; return true;} return false;}
template<class T> bool chmax(T& a, T b) {if (a < b) {a = b; return true;} return false;}
ll safemod(ll A, ll M) {return (A % M + M) % M;}
ll divfloor(ll A, ll B) {if (B < 0) {return divfloor(-A, -B);} return (A - safemod(A, B)) / B;}
ll divceil(ll A, ll B) {if (B < 0) {return divceil(-A, -B);} return divfloor(A + B - 1, B);}
template<class T> void sortunique(vector<T> &V) {sort(V.begin(), V.end()); V.erase(unique(V.begin(), V.end()), V.end());}
#define FINALANS(A) do {cout << (A) << '\n'; exit(0);} while (false)

int main()
{
  ll N;
  cin >> N;

  vector<vector<bool>> A(2 * N - 1, vector<bool>(2 * N - 1, false));
  for (ll i = N; i < 2 * N - 1; i++)
  {
    for (ll j = 0; j < i + 1; j++)
    {
      A.at(i).at(j) = true;
    }
  }
  for (ll i = 1; i < N; i++)
  {
    A.at(i).at(2 * (N - i - 1)) = true;
    A.at(i).at(2 * (N - i - 1) + 1) = true;
    for (int j = 2 * N - 2; j > 2 * N - 2 - (i - 1); j--)
    {
      A.at(i).at(j) = true;
    }
  }
  A.at(0).at(2 * (N - 1)) = true;

  /*
  for (ll i = 0; i < 2 * N - 1; i++)
  {
    for (ll j = 0; j < 2 * N - 1; j++)
    {
      cerr << A.at(j).at(i);
    }
    cerr << endl;
  }
  //*/

  cout << 2 * N - 1 << endl;
  for (ll j = 0; j < 2 * N - 1; j++)
  {
    for (ll i = 0; i < 2 * N - 1; i++)
    {
      if (A.at(i).at(j))
        cout << i + 1 << " ";
    }
    cout << endl;
  }
}