#include<fstream.h>
int cmmdc(long int a,long int b)
{
 if(!b)return a;
return cmmdc(b,a%b);
}
int main()
{
long int n,r,i,j,nr=0;
ifstream f("fractii.in");
f>>n;
f.close();
ofstream g("fractii.out");
nr=4*n-5;
for(i=2;i<=n-1;i++)
{
for(j=i+2;j<=n;j++)
{
r=cmmdc(i,j);
if(r==1)
nr=nr+2;
}}
g<<nr;
g.close();
return 0;
}