#include <stdio.h>  
      
   int n;  
    int contor;  
     
   int main(void)  
    {  
     
       FILE* f=fopen ("fractii.in","r");  
       fscanf (f,"%d",&n);  
       fclose (f);  
     
     contor=0;  
     
       for (int i=1;i<=n;i++)  
       {  
           int ln=i;  
     
           int totient=ln;  
           int p1=1;  
          int p2=1;  
           for (int j=2;j<=ln;j++)  
          {  
               if (ln%j==0)  
              {  
                  p1=p1*(j-1);  
                  p2=p2*j;  
               }  
               while (ln%j==0)  
                   ln=ln/j;  
           }  
     
          totient=(totient*p1)/p2;  
     
           contor+=totient;  
       }  
     
       contor=contor+contor-1;  
     
       f=fopen ("fractii.out","w");  
       fprintf(f,"%d",contor);  
       fclose (f);  
     
      return 0;  
   }