#include<fstream>

using namespace std;

ifstream in("fractii.in");
ofstream out("fractii.out");

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

int main()
{
	int n,i,j,contor=1;
	in>>n;
	for(i=1;i<n;++i)
		for(j=i+1;j<=n;++j)
			if(cmmdc(i,j)==1)
				contor+=2;
	out<<contor;
}