#include<fstream.h>  
#include<math.h>

int prim(long a)
{int b=sqrt(a);
for(int i=2;i<=b;++i)
	if(a%i==0) return 0;
return 1;
}

int main()
{long int n,i,j,nr=0,a,b,t,d;
ifstream f("fractii.in");
ofstream g("fractii.out");
f>>n;
nr=n+n/2+n%2;
for(i=3;i<=n;i++)
    if(prim(i)) nr+=(n-n/i); else
    for(j=1;j<=n;j++)
    {a=i<=j?i:j;
	b=j>=i?j:i;
	 t=0;
	d=2;
	while(a%d==0)  
            {a/=d;  
            if(b%d==0) t=1;}    
   for(d=3;d<=a && t==0; d+=2)  
        while(a%d==0 && t==0)  
            {a/=d;  
            if(b%d==0) t=1;}  
    if(t==0) nr++;  
     }  
  
g<<nr;  
f.close(); g.close();  
return 0; }