/**
*@Author : Shreyas Pandey
*Team : AntiPython
*[2020-09-19 10:16]
**/

#include<bits/stdc++.h>
#define ll long long
#define ld long double
#define vll vector<ll>
#define vvll vector< vll >  // vector<vector<vll>>
#define vld vector< ld >
#define vvld vector< vld > // vector <vector <long double>>
#define pll pair<ll ,ll >
#define vpll vector< pll >
#define mp make_pair
#define pb push_back
#define MOD 1000000007
#define endl "\n"
#define flash ios_base::sync_with_stdio(false);cin.tie(NULL);
#define test ll t;read(t);while(t--)
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define fst first
#define scd second

#define forn(i,n) for(ll (i) = 0 ; (i) < (n) ; ++(i))
#define for1(i,n) for(ll (i) = 1 ; (i) <= (n) ; ++(i))
#define forr(i,n) for(ll (i) = (n)-1 ; (i)>=0 ; --(i))
#define forab(i,a,b,c) for(ll (i) = a ; (i) <= (b) ; (i)+=(c))

using namespace std;
void online_judge()
{
#ifndef ONLINE_JUDGE
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
  freopen("error.txt", "w", stderr);
#endif
}

////////////////////////////////////////////////////////////////// Inputs ////////////////////////////////////////////////////////////////////////////////////
template <typename T>
void read(T &x) {
  cin >> x;
}

template <typename T , typename T0>
void read(T &x, T0 &y) {
  cin >> x >> y;
}

template <typename T , typename T0 , typename T1>
void read(T &x, T0 &y, T1 &z) {
  cin >> x >> y >> z;
}

template <typename T , typename T0 , typename T1 , typename T2>
void read(T &x, T0 &y, T1 &z, T2 &w) {
  cin >> x >> y >> z >> w;
}

template <typename T , typename T0>
void read(pair< T , T0 > &p) {
  cin >> p.fst >> p.scd;
}

template <typename T>
void read(vector< T > &oneD) {
  for (ll i = 0; i < oneD.size(); i++) {
    read(oneD[i]);
  }
}

template <typename T>
void read(T oneD[] , int n) {
  for (ll i = 0; i < n; i++) {
    read(oneD[i]);
  }
}

/////////////////////////////////////////////////////////////////////////// Outputs ////////////////////////////////////////////////////////////////////////////

template <typename T>
void write(T &x) {

  cout << x << " ";
}

template <typename T , typename T0>
void write(T &x, T0 &y) {
  cout << x << " " << y << "\n";
}

template <typename T , typename T0 , typename T1>
void write(T &x, T0 &y, T1 &z) {
  cout << x << " " << y << " " << z << "\n";
}

template <typename T , typename T0 , typename T1 , typename T2>
void write(T &x, T0 &y, T1 &z, T2 &w) {
  cout << x << " " << y << " " << z << " " << w << "\n";
}

template <typename T , typename T0>
void write(pair< T , T0 > &p) {
  write(p.fst);
  write(p.scd);
  cout << endl;
}

template <typename T>
void write(vector< T > &oneD) {
  for (ll i = 0; i < oneD.size(); i++) {
    write(oneD[i]);
  }
  cout << endl;
}

template <typename T>
void write(T oneD[] , int n) {
  for (ll i = 0; i < n; i++) {
    write(oneD[i]);
  }
  cout << endl;
}

template <typename T , typename T0>
void write(map< T , T0 > &mpp) {
  for (auto it : mpp) {
    write(it.fst);
    cout << ": ";
    write(it.scd);
    cout << "\n";
  }
  cout << endl;
}

///////////////////////////////////////////////////////////////////////// Maths //////////////////////////////////////////////////////////////////////////////

vll sieve;
void Sieve(int N) {
  const ll maxn = N;
  sieve.resize(maxn);
  forn(i, maxn) sieve[i] = i;
  sieve[1] = -1;
  sieve[0] = -1;
  forab(i, 2, maxn, 1) if (i == sieve[i]) for (ll j = 2 * i ; j < maxn ; j += i) if (sieve[j] == j) sieve[j] = i;
}


ll extended_GCD(ll a , ll b , ll &x , ll &y) {
  if (a == 0) {
    x = 0;
    y = 1;
    return b;
  }
  ll x1 , y1;
  ll gcd = extended_GCD(b % a , a , x1 , y1);
  x = y1 - (b / a) * x1;
  y = x1;
  return gcd;
}
long long binpow(long long a, long long b, long long m) {
  a %= m;
  long long res = 1;
  while (b > 0) {
    if (b & 1)
      res = res * a % m;
    a = a * a % m;
    b >>= 1;
  }
  return res;
}


ll modinv(ll a , ll mod = MOD) {
  ll x , y;
  extended_GCD(a , mod , x , y);
  if (x < 0) x += mod;
  return x;
}
ll int sum_form(ll int k)
{
  return ((k * (k + 1)) / 2);
}
ll int binarySearch(ll int l, ll int r, ll int n)
{
  ll ans = -1;
  while (l <= r)
  {
    ll int mid = l + (r - l) / 2;
    ll sum_l = sum_form(mid);
    ll sum_r = sum_form(n) - sum_l;
    if (sum_l == sum_r)
    {
      ans = mid;
      return ans;
    }
    else if (sum_l > sum_r)
    {
      r = mid - 1;
    }
    else
    {
      ans = mid;
      l = mid + 1;
    }
  }
  return ans;
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////Segment Tree//////////////////////////////////////////////////////////////////////////////


//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void solve()
{
  ll n;
  cin >> n;
  ll ans = 0;
  for(int i = 1;i<n;++i)
  {
    ans += (n-1)/i;
  }
  cout << ans <<"\n";

}

int main()
{
  flash
  online_judge();
  solve();
  return 0;
}


Measured memory_bytes: 3676