#include <iostream>
#include <fstream>
using namespace std;
int cmmdc(int a, int b)
{
	if(!b) return a;
	return cmmdc(b, a%b);
}
int get_nr(int nr)
{
	int sum=0;
	for (int i=1;i<=nr;i++)
	{
		for(int j=1;j<=nr;j++)
		{
			if(cmmdc(i, j) == 1)
			{
				cout<<i<<" "<<j<<endl;
				++sum;
			}
		}
	}
	return sum;
}
int main()
{
	ifstream in("fractii.in");
	ofstream out("fractii.out");

	int nr;
	in>>nr;
	out<<get_nr(nr);
}