#include <stdio.h>

FILE *in,*out;
int i,n,s;

int fi(int n) 
     { 
       int result = n; 
       for(i=2;i*i<= n;i++) 
       { 
         if (n % i == 0) result -= result / i; 
         while (n % i == 0) n /= i; 
       } 
       if (n > 1) result -= result / n; 
       return result; 
     } 
     
int main()
{
    s=0;
    in=fopen("fractii.in","r");
    fscanf(in,"%d",&n);
    fclose(in);
    for(i=0;i<n;i++)
    {
                    s=s+fi(i);
                    }
    out=fopen("fractii.out","w");
    fprintf(out,"%d",s);
    fclose(out);
    return 0;
    }