#include<stdio.h>

long prime(long x,long y)
{
   if(!y) return x;
   return prime(y,x%y);
}

int main()
{
    FILE *fin,*fout;
    long n,i,j,s=0;

    fin=fopen("fractii.in","rt");
    fscanf(fin,"%ld",&n);
    fclose(fin);

    s+=2*n-1;
    for(i=2;i<=n;i++)
        for(j=i+1;j<=n;j++)
            if(prime(i,j)==1) s+=2;

    fout=fopen("fractii.out","wt");
    fprintf(fout,"%ld",s);
    fclose(fout);



    return 0;
}