/*

  ** author:  im_sk
  ** created: 19-09-2020 

*/

#include<bits/stdc++.h>

#define int long long
#define pb push_back
#define eb emplace_back
#define ff first
#define ss second
#define len(a) (int)a.size()
#define all(a) (a).begin(), (a).end()
#define pq priority_queue
#define umap unordered_map
#define uset unordered_set
#define lb lower_bound
#define ub upper_bound

#define f_or(i, a, b, s) for (int i=(a); (s)>0?i<(b):i>(b); i+=(s))
#define f_or1(e) f_or(i, 0, e, 1)
#define f_or2(i, e) f_or(i, 0, e, 1)
#define f_or3(i, b, e) f_or(i, b, e, 1)
#define f_or4(i, b, e, s) f_or(i, b, e, s)
#define get5(a, b, c, d, e, ...) e
#define f_orc(...) get5(__VA_ARGS__, f_or4, f_or3, f_or2, f_or1)
#define forr(...) f_orc(__VA_ARGS__)(__VA_ARGS__)
#define forn(x , a) for(auto &x : a)

using namespace std ;

using vi   = vector<int> ;
using vs   = vector<string> ;
using vvi  = vector<vi> ;
using pii  = pair<int,int> ;
using vpii = vector<pii>  ;
using mii  = map<int,int> ;
using umii = unordered_map<int,int> ;

template <typename A, typename B>
string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string& s) {
   return '"' + s + '"';
}

string to_string(const char* s) {
   return to_string((string) s);
}

string to_string(bool b) {
   return (b ? "true" : "false");
}

string to_string(vector<bool> v) {
   bool first = true;
   string res = "{";
   for (int i = 0; i < static_cast<int>(v.size()); i++) {
         if (!first) {
            res += ", ";
         }
   first = false;
   res += to_string(v[i]);
   }
   res += "}";
   return res;
}

template <size_t N>
string to_string(bitset<N> v) {
   string res = "";
   for (size_t i = 0; i < N; i++) {
         res += static_cast<char>('0' + v[i]);
   }
   return res;
}

template <typename A>
string to_string(A v) {
   bool first = true;
   string res = "{";
   for (const auto &x : v) {
         if (!first) {
               res += ", ";
         }
    first = false;
    res += to_string(x);
   }
   res += "}";
   return res;
}

template <typename A, typename B>
string to_string(pair<A, B> p) {
   return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
   return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
   return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
   cerr << " " << to_string(H);
   debug_out(T...);
}

#ifndef ONLINE_JUDGE
#define debug(...) cerr<<"LINE ("<< __LINE__ << ") : [" << #__VA_ARGS__ << "] -> ", debug_out(__VA_ARGS__)
#else
#define debug(...)
#endif

int32_t main(){
   ios::sync_with_stdio(false);
   cin.tie(nullptr);
#ifndef ONLINE_JUDGE
   //freopen("in1.txt", "r", stdin);
#endif
   int n ;
   cin >> n ;
   int tuples = 0 ; 
   forr(i , 1 , n){
      int ans = 1 ;
      int x = i ;
      int cnt = 0 ; 
      while(x %  2 == 0){
           cnt++ ; 
           x/=2 ; 
      }
      if(cnt != 0 ){
         ans = cnt + 1 ; 
      }
      for(int j = 3 ; j * j <=x ; j+=2){
         cnt = 0 ; 
         while(x % j == 0){
            cnt++ ; 
            x/=j ; 
         }
         ans *= (cnt + 1) ;
      }
      if(x > 1) ans*=2 ;
      tuples += ans ; 
   }
   cout << tuples  ; 

#ifndef ONLINE_JUDGE
    cerr << "\n\nTime elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";
#endif

   return 0 ;
}




Measured memory_bytes: 3652