#include <iostream>
#include<fstream>
using namespace std;
int cmmdc(int a,int b)
{
    while(a!=b)
      if(a>b)
        a=a-b;
       else
        b=b-a;
    return a;
}
int main()
{
    int p,q,n,frac=0;
    ifstream f("fractii.in");
    ofstream g("fractii.out");
    f>>n;
    for(p=1;p<=n;p++)
        for(q=1;q<=n;q++)
    {

        if(p%q!=0 && cmmdc(p,q)==1)
              {
                  cout<<p<<" "<<q<<endl;
                  frac++;
              }
    }
    g<<frac+n;
    f.close();
    g.close();

    return 0;
}