//Diaconescu Ion
#include <iostream>
using namespace std;
int n,q,p,nr;
int main()
{cin>>n;
nr=0;
for (p=1;p<=n;p++)
{
for (q=1;q<=n;q++)
{
nr=nr+1;
if (p&&q!=1 && p%q==0) nr=nr-1;

}
}
cout<<nr;
    return 0;
}