#include <cstdio>
#include <cmath>

using namespace std;

int nrdiv (int n)
{
    int count = 0, lim = (int)sqrt((double)n);
    for(int i=2; i<=lim; i++)
        if(n%i==0)
            count++;

    if(lim * lim == n)
        count--;
    return count;
}

int main()
{
    freopen("fractii.in","r",stdin);
    freopen("fractii.out","w",stdout);
    int n, result = 0;

    scanf("%d",&n);

    for(int i=2; i<=n; i++)
        result += nrdiv(i) + (10/i);

    printf("%d",result + n);
    return 0;
}