#include<fstream>
using namespace std;
ifstream fi("tije.in");
ofstream fo("tije.out");
int n,i,j,k;
int main()
{
    fi>>n;
    for(i=1; i<=n; i++)
    {
        for(j=1; j<=i; j++)
            fo<<i<<" "<<n+1<<"\n";
        for(j=i+1; j<=n; j++)
        {
            for(k=1; k<=j-2; k++)
                fo<<j<<" "<<i<<"\n";
            fo<<j<<" "<<n+1<<"\n";
            for(k=1; k<=j-2; k++)
                fo<<i<<" "<<j<<"\n";
            fo<<i<<" "<<j<<"\n";
        }
        for(j=1; j<=n; j++)
            fo<<n+1<<" "<<i<<"\n";
    }
    fi.close();
    fo.close();
    return 0;
}