#include<fstream.h>
int divizor(int x,int y)
{while(x!=y)
	{if(x>y)x=x-y;
   else y=y-x;}
return x;
}

int main()
{fstream f("fractii.in", ios::in);
fstream g("fractii.out", ios::out);
int nr,n,i,j;
f>>n;
nr=2*n;
for(i=2;i<=n;i++)
	for(j=2;j<=n;j++)
		if(i-j==1||i-j==-1)nr++;
      else if(divizor(i,j)==1)nr++;
g<<nr;
f.close();
g.close();
}