#include<iostream.h>
#include<fstream.h>

int prime (long a, long b)
{int k=2, g=1;
while((k<=a)&&(k<=b)&&(g==1))
	{if((a%k==0)&&(b%k==0))
		g=0; k++;}
return g;}

int main()
{long n,i,j; int suma;
fstream f ("fractii.in", ios::in);
f>>n; f.close();

suma=2*n-1;

for(i=2; i<=n; i++)
	for(j=2; j<=n; j++)
		if(prime(i,j)==1)
			suma++; 
		fstream g("fractii.out", ios::out);
		g<<suma; g.close();
}