#include<fstream.h>

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

unsigned long cmmdc(unsigned long a, unsigned long b)
 {
                   if(a==b) return a;
                   if(a>b)  a-=b; else b-=a; 
                   return cmmdc(a,b); 
 }                   
     
          
void vector1(unsigned long n,int prime[1000000])
   {
                unsigned long aux;      
                for(unsigned long i=2; i<=n; i++) 
                   { aux=1;
                     for(unsigned j=2; j<i; j++)
                        if( cmmdc(i,j)==1 ) aux++;
                     prime[i]=aux;
                   }
   }

                
int main()
 {
          unsigned long n,i,cont=0;
          int prime[1000000];
          prime[1]=0;
          fin>>n;
          vector1(n,prime); 
          prime[1]=0; 
          for(i=1; i<=n; i++)
              cont+=prime[i]; 
          fout<<cont*2+1;
 }