#include <iostream>
#include <fstream>
long n,nr;
void main(){
std::ifstream in("fractii.in");
std::ofstream out("fractii.out");
in>>n;
for (long i=1;i<=n;i++)
 for (long j=1;j<=n;j++)
	 if (i%j!=0){
		 out>>i>>" ">>j;
		 nr=nr+1;}
out<<nr;
}