#include <iostream>
#include <fstream>
using namespace std;

int main()
{

ifstream f ("fractii.in");
ofstream g ("fractii.out");

    int a,i,j;

    f>>a;
    int numarare=0;
    for(i=1;i<=a;i++)
    {
        for(j=1;j<=a;j++)
        {
          if((i%j!=0)||(j==1))
         {

          ++numarare;
        cout<<" "<<i<<" "<<j;
        cout<<endl;}
        }
    }
    g<<numarare;
    return 0;
}