#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
string to_string(string s) { return '"' + s + '"'; }
string to_string(const char* s) { return to_string(string(s)); }
string to_string(bool b) { return to_string(int(b)); }
string to_string(vector<bool>::reference b) { return to_string(int(b)); }
string to_string(char b) { return "'" + string(1, b) + "'"; }
template <typename A, typename B>
string to_string(pair<A, B> p) { return "(" + to_string(p.first) + ", " + to_string(p.second) + ")"; }
template <typename A>
string to_string(A v) {
	string res = "{";
	for (const auto& x : v) res += (res == "{" ? "" : ", ") + to_string(x);
	return res + "}";
}
void debug() { cerr << endl; }
template <typename Head, typename... Tail>
void debug(Head H, Tail... T) {
	cerr << " " << to_string(H);
	debug(T...);
}
#define db(...) cerr << "[" << #__VA_ARGS__ << "]:", debug(__VA_ARGS__)
#else
#define db(...) 42
#endif
typedef long long ll;
typedef long double ld;
int main() {
	int k;
	scanf("%d", &k);
	ll ans = 0;
	for (int a = 1; a <= k; ++a) {
		for (int ab = a; ab <= k; ab += a) {
			int nc = k / ab;
			ans += nc;
		}
	}
	printf("%lld\n", ans);
}

/*pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")*/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define FOR(i, a, n) for (ll i = (ll)a; i < (ll)n; i++)
#define RFOR(i, a, n) for (ll i = (ll)n - 1; i >= (ll)a; i--)
#define rep(i, n) FOR(i, 0, n)
#define rrep(i, n) RFOR(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define bra(firstsecond) '(' << first< ',' << second< ')'
constexpr ll MOD = 1000000007;
//constexpr ll MOD = 998244353;
ll INF = 1001001001001;
long double EPS = 1e-8;
long double PI = 3.141592653589793238;
template <typename T>
void remove(std::vector<T> &vector, unsigned int index)
{
   vector.erase(vector.begin() + index);
}

using Graph = vector<vector<pair<ll,ll>>>;


// MOD確認


int main(){
  ll K;
  cin >> K;
  ll ans = 0;
  ll cnt = 0;
  ll m = 0;
  FOR(i,1,K+1){
    FOR(j,1,K / i + 1){
      ll l = 1,r = INF;
      while(r-l > 1){
        ll mid = (l+r)/2;
        if(i * j * mid > K) r = mid;
        else l = mid;
      }
      ans += l;
    }
  }
  cout << ans << endl;
}