#include <fstream>
#include <iostream>
using namespace std;

ifstream in("fractii.in");
ofstream out("fractii.out");

int log(int n,int p)
{
    int c=0;
    while(n>=p)
    {
        n/=p;
        c++;
    }
    return c;
}

int sum(int p)
{
    return (p*(p-1))/2;
}

int main()
{

    int n,part;
    in>>n;
    int cnt=n-1;
    for(int i=2;i<n;i++)
    {
        cnt+=n-i;
        part=n/i;
        cnt-=(sum(part));
        cnt+=sum(log(n,i)-1);
    }
    cnt=2*cnt+1;
    out<<cnt;
}