#include <iostream>
#include <fstream>
using namespace std;
long long int n,i,j;
int main()
{
    ifstream fin("submultimi.in");
    ofstream fout("submultimi.out");
    fin>>n;
    for(i=1;i<=n-2;i++)
    {
        fout<<i<<"\n";
        for(j=i+1;j<=n;j++)fout<<i<<" "<<j<<"\n";
        for(j=i;j<=n;j++)fout<<j<<" ";
        fout<<"\n";
    }
    fout<<n-1<<"\n"<<n-1<<" "<<n<<"\n"<<n;
    fin.close();
    fout.close();
    return 0;
}