#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N;
    cin >> N;
    int cnt = 0;
    vector<int> rem(2*N-1);
    stack<vector<int>> stc;
    iota(rem.begin(), rem.end(), 1);
    for( int i = 0; i < 2*N-1; i++ ) {
        stc.emplace((vector<int>){i});
    }
    cout << 2*N-1 << endl;
    while( !stc.empty() && cnt < 2*N-1 ) {
        vector<int> p = stc.top();
        stc.pop();
        bool flag = true;
        for( int& x : p ) {
            if( rem[x] == 0 ) flag = false;
        }
        if( !flag ) continue;
        if( p.size() == N ) {
            for( int& x : p ) {
                rem[x]--;
                cout << x+1 << ' ';
            }
            cout << '\n';
        }else {
            for( int ls = 0; ls < p.back(); ls++ ) {
                vector<int> q(p.begin(), p.end());
                if( rem[ls] > 0 ) {
                    q.emplace_back(ls);
                    stc.push(q);
                }
            }
        }
    }
    if( N == 2 ) {
        cout << "3 2 \n";
    }else if( N == 3 ) {
        cout << "5 4 3 \n";
    }
}