#include <bits/stdc++.h>
using namespace std;
vector<long long int> divisor(long long int N) {
  vector<long long int> p;
  for (long long int q = 1; q * q <= N; q++) {
    if (N % q == 0) {
      p.push_back(q);
      if (N / q != q) {
        p.push_back(N / q);
      } else {
      }
    } else {
    }
  }
  sort(p.begin(), p.end());
  return p;
}
int main() {
  long long int N;
  cin >> N;
  long long int kariN;
  long long int counter = 0;
  for (long long int i = 1; i < N; i++) {
    vector<long long int> A(0);
    kariN = N - i;
    A = divisor(kariN);
    counter += A.size();
  }
  cout << counter;
  return 0;
}
