func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 2e6 + 10;   const int INF = 1e9 + 9;   const int B = 1e9 + 7;   long long p[N], s[N];   int fp(int first) {     return first == p[first] ? first : p[first] = fp(p[first]);   }   void u(int a, int b, int d) {     s[fp(a)] += 4 * d;     if (fp(a) == fp(b)) return;     s[fp(b)] += s[fp(a)];     p[fp(a)] = fp(b);   }   int main() {     ios_base ::sync_with_stdio(0);     cin.tie(0);     int n;     cin >> n;     vector<long long> a(n + 1);     long long ans = 0;     for (int i = int(2); i <= int(n); ++i) p[i] = i, s[i] = 0;     for (int i = int(n); i >= int(2); --i)       for (int j = 2; i * j <= n; ++j) u(i, i * j, j);     for (int i = int(2); i <= int(n); ++i) ans = max(ans, s[fp(i)]);     cout << ans <<   n ;     return 0;   }   