#include <iostream>
#include <fstream>
using namespace std;
int cmmdc(int a,int b){
	if (a==0 || b==0)
		return 0;
	else if (a==b)
		return a;
	else if (a>b)
		return cmmdc(a-b,b);
	else 
		return cmmdc(a,b-a);
}
int main(){
	ifstream fin("fractii.in");
	ofstream fout("fractii.out");
	int n,i,j,sum;
	sum=0;
	fin>>n;
	for(i=1;i<=n-1;i++)
		for(j=i+1;j<=n;j++)
			if (cmmdc(i,j)==1)
				sum++;
	fout<<sum;
	return 0;

}