#include <iostream>
using namespace std;
int nrdiv(int num)
{
int nr=0, j;
for (j=1; j*j<num; ++j)
if (num%j==0) nr+=2;
if (j*j==num) ++nr;
return nr;
}
int main()
{
int n, indtermen, xn=1;
cin >> n;
for (indtermen=2; indtermen<=n; ++indtermen)
xn = xn + nrdiv(indtermen);
cout << xn;
return 0;
}