#include<iostream>
#include<fstream>
using namespace std;
int n,p=1,p1=1;
int main()
{
    ifstream f("submultimi.in");
    ofstream g("submultimi.out");
    f>>n;
    while(p1<=n)
    {
        for(int i=p;i<=p1;i++)
        {
            g<<i<<" ";
        }
        if(p1==n)
        {
            p++;
            p1=p;
        }
        else
        {
            p1++;
        }
        g<<"\n";
        if(p1-p>1)
        {
            g<<p<<" "<<p1<<"\n";
        }
    }
}