#include <iostream>
#include <cstdio>
FILE *f,*g;
using namespace std;

int main()
{
    f=fopen("fractii.in","r");
    g=fopen("fractii.out","w");
    long i,j,N,k;
    fscanf(f,"%ld",&N);
    k=2*N-1;
    fclose(f);
    for(i=2;i<N;i++)
    {
        for(j=i+1;j<=N;j++)
        {
            if( i%j!=0 && j%i!=0 )
            {
                k+=2;
            }
        }
    }
    fprintf(g,"%ld",k);
    fclose(g);
    return 0;
}