#include <iostream>
#include <fstream>

using namespace std;

void nez(int N, int &k, int sz, int n);

int main() {
	int N;
	ifstream in("fractii.in");
	in >> N;
	int k = 0;
	for (int sz = 1;sz <= N;sz++)
		for (int n = 1;n <= N;n++)
			nez(N,k,sz,n);
	ofstream out("fractii.out");
	out << k;
	cout << k;
}

void nez(int N, int &k, int sz, int n) {
	if (sz == 1 || n == 1) {
		k++; cout << sz << " " << n << endl;
		return;
	}
	int kisebb;
	if (sz > n) kisebb = n;
	else kisebb = sz;
	for (int i = 2; i <= kisebb; ++i)
		if (sz%i == 0 && n%i == 0) return;
	k++; cout << sz << " " << n << endl;
}