#include<fstream>
using namespace std;
int v1[100000000], suma=0, j, i;
int main()
{
ifstream in ("fractii.in");
ofstream out ("fractii.out");
int n;
in>>n;
for(i=1; i<=n;i++)
{
    v1[i-1]=i;
}
for(i=0;i<n;i++)
    {
        for(j=0;j<n;j++)
        {
            if(v1[i]%v1[j]!=0)
            {
            suma++;
            }
        }
    }
out<<suma+n;
}