#include <bits/stdc++.h>   using namespace std;   const int inf = 0x3f3f3f3f;   const int Maxn = 10010;   int a[Maxn];   int tot = 0;   int main() {     int n;     cin >> n;     long long sum = 0;     for (int i = 2; i <= n; i++) {       for (int j = 2 * i; j <= n; j += i) {         sum += 4ll * (j / i);       }     }     cout << sum << endl;     return 0;   }   