#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll,ll>;
#define rep(i, n) for(ll i = 0; i < n; i++)
#define all(x) (x).begin(),(x).end()
template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;}

int main(){
    ll n;
    cin >> n;
    cout << 2*n-1 << endl;
    vector<vector<int>> ans(2*n-1,vector<int>(n));
    for(int i=1;i<=2*n-1;i++){
        if(i<=n){
            ans[i-1][0] = i;
            rep(j,i-1) ans[2*n-2-j][n-i] = i;
        }else{
            rep(j,i) ans[j][i-n] = i;
        }
    }
    for(auto v:ans){
        for(auto x:v) cout << x << " ";
        cout << endl;
    }
    return 0;
}