#include <bits/stdc++.h>   using LL = int64_t;   int main() {     std::ios::sync_with_stdio(false);     std::cin.tie(nullptr);     int n;     std::cin >> n;     std::vector<int> a(n);     for (int &i : a) std::cin >> i;     std::sort(a.begin(), a.end());     int maxa = a.back();     std::vector<std::vector<int>> mx(maxa + 1);     for (auto &i : mx) i.assign(2, -1);     std::vector<int> cnt(maxa + 1);     for (int i : a) ++cnt[i];     for (int i = 1; i <= maxa; ++i) {       if (cnt[i] >= 2)         mx[i][0] = mx[i][1] = i;       else if (cnt[i] == 1) {         mx[i][0] = i;         mx[i][1] = mx[i - 1][0];       } else         mx[i] = mx[i - 1];       cnt[i] += cnt[i - 1];     }     LL ans = 0;     for (int y = 2; y <= maxa; ++y) {       int more[] = {-1, -1};       LL cnty = 0;       for (int k = 1; k <= maxa / y; ++k)         cnty += (LL)k * (cnt[std::min((k + 1) * y - 1, maxa)] - cnt[k * y - 1]);       for (int k = maxa / y; k >= 0; --k) {         more[1] =             std::max(more[1], mx[std::min((k + 1) * y - 1, maxa)][0] - k * y);         if (more[0] < more[1]) std::swap(more[0], more[1]);         more[1] =             std::max(more[1], mx[std::min((k + 1) * y - 1, maxa)][1] - k * y);         int x = std::min((LL)(k * y + more[0]) / 2, cnty - k);         if (x >= 2) ans = std::max(ans, LL(x) * y);         if (more[1] != -1) {           x = std::min((LL)k * y + more[1], cnty - 2 * k);           if (x >= 2) ans = std::max(ans, LL(x) * y);         }         if (n - cnt[std::max(0, k * y + more[0] - 1)] >= 2) {           x = std::min((LL)k * y + more[0], cnty - 2 * k - 1);           if (x >= 2) ans = std::max(ans, LL(x) * y);         }       }     }     std::cout << ans <<   n ;     return 0;   }   