#include <iostream.h>

int euclid(int a, int b)  
{
int c;  
    while (b) {  
        c = a % b;  
        a = b;  
        b = c;  
    }  
    return a; 
}  

int fractii(int n)
{
int count=0;
   count=2*n-1;
    for (int i=2;i<=n;i++) 
     // if (i%2==0) for(int k=3;k<=n;k+=2)
                          //if (euclid(i,k)==1) count++;
                 
                 for(int j=2;j<=n;j++)
                         if (euclid(i,j)==1) count++;
return count;
}



   
   
int  main()  
     
   {  
   FILE *f,*g;  
   long n,nr;
   f=fopen("fractii.in","r");
		  fscanf(f,"%ld",&n);
   nr=fractii(n);
   g=fopen("fractii.out","w+");  
   fprintf(g,"%ld",nr);
   
   fclose(f);  
   fclose(g);  
   return 0;  
   }