#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int DY[]{1, 0, -1, 0}, DX[]{0, -1, 0, 1};
constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1}, DX8[]{0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U> inline bool chmax(T& a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U> inline bool chmin(T& a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

int main() {
  int n; cin >> n;
  vector ans(n * 2 - 1, vector<int>{n * 2 - 1});
  vector group(1, vector<int>(n * 2 - 1));
  iota(ALL(group.front()), 0);
  for (int i = 1; i < n * 2 - 1 - i; ++i) {
    sort(ALL(group), [&](const vector<int>& a, const vector<int>& b) -> bool {
      return a.size() > b.size();
    });
    int p = i, q = n * 2 - 1 - i, x = p, y = q;
    vector<vector<int>> nxt;
    for (const vector<int>& g : group) {
      if (x < y) {
        swap(p, q);
        swap(x, y);
      }
      const int num = min(static_cast<int>(g.size()) / 2, y);
      if (num > 0) {
        nxt.emplace_back();
        REP(i, num) {
          ans[g[i]].emplace_back(q);
          --y;
          nxt.back().emplace_back(g[i]);
        }
      }
      nxt.emplace_back();
      FOR(i, num, g.size()) {
        ans[g[i]].emplace_back(p);
        --x;
        nxt.back().emplace_back(g[i]);
      }
    }
    group.swap(nxt);
  }
  cout << n * 2 - 1 << '\n';
  REP(i, n * 2 - 1) REP(j, n) cout << ans[i][j] << " \n"[j + 1 == n];
  return 0;
}