#include<fstream>

using namespace std;

int cmmdc(int a, int b)
{
	int r;
	r=a%b;
	while(r)
	{
		a=b;
		b=r;
		r=a%b;
	}
	return b;
}

int main()
{
	int n, i, j, k=0;
	ifstream in("fractii.in");
	in>>n;
	for(i=2; i<=n; i++)
	{	
		for(j=1; j<i; j++)
		{	
			if(cmmdc(i,j)==1)
				k+=2;
			if(i%2==0)
				j++;
		}
	}
	ofstream out("fractii.out");
	out<<k-3+n;
	return 0;
}