#include<stdio.h>

int cmmdc(int a,int b)
{
   int r;
   r=a%b;
   while(r)
   {
       a=b;
       b=r;
       r=a%b;
   }
   return b;
}

int main()
{
    int i=0;
    int j=0;
    int N=0;

    FILE *f=fopen("fractii.in","r");
    FILE *g=fopen("fractii.out","w");

    fscanf(f,"%d",&N);
   
    int contor=(N-1)*2+1;
    for(i=3;i<=N;i++)
        for(j=2;j<i;j++)
        {
            if(cmmdc(i,j)==1)
            {
                contor+=2;
            }
        }
    fprintf(g,"%d",contor);
    fclose(f);
    fclose(g);
    return 0;
}