28237
 13190
 39914
 81367
 8554
 61106
 67448
 39004
 22308
 16054
 71468
 60501
 100
 300
 59632
 90783
 5611
 1000
 69475
 69753
 10
 5
 582
 8
 36961
 5071
 20
 53213
 92775
 28738
 100000
 92280
 37944
 9
 2627
 7
 3

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#include <bits/stdc++.h>
using namespace std;
template <class T>
void show(const vector<T> &a) {
  for (T x : a) cout << x << " ";
  cout << '\n';
}
const long long sze = 3e5 + 50, oo = 1e18 + 500, mod = 1000000007;
const long double eps = 5e-10, PI = 2 * acos(0.0);
vector<long long> vertices[sze];
vector<char> visit(sze, false);
vector<long long> arr(sze, 0);
long long n, m, k;
long long d = 0;
long long cnt = 0;
string s;
long long x, y;
bool sv[sze];
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> n;
  for (long long i = 2; i <= n; i++) {
    if (!sv[i]) {
      for (long long j = i * i; j <= n; j += i) {
        sv[j] = true;
      }
    }
  }
  long long ans = 0;
  for (long long i = 2; i <= n; i++) {
    if (!sv[i]) {
      for (long long j = 2; j <= n; j++) {
        if (!sv[j]) {
          cnt = 0;
          for (long long z = i * j; z <= n; z = z * j) {
            cnt++;
          }
          if (cnt) ans += (2 * (cnt + 1)) * j;
        }
      }
    }
  }
  cout << ans;
  return 0;
}
