#include #pragma GCC diagnostic ignored "-Wsign-compare" #pragma GCC diagnostic ignored "-Wsign-conversion" #define NDEBUG using i32 = int32_t; using i64 = int64_t; using u32 = uint32_t; using u64 = uint64_t; using uint = unsigned int; using usize = std::size_t; using ll = long long; using ull = unsigned long long; using ld = long double; template constexpr T popcount(const T u) { return u ? static_cast(__builtin_popcountll(static_cast(u))) : static_cast(0); } template constexpr T log2p1(const T u) { return u ? static_cast(64 - __builtin_clzll(static_cast(u))) : static_cast(0); } template constexpr T msbp1(const T u) { return log2p1(u); } template constexpr T lsbp1(const T u) { return __builtin_ffsll(u); } template constexpr T clog(const T u) { return u ? log2p1(u - 1) : static_cast(u); } template constexpr bool ispow2(const T u) { return u and (static_cast(u) & static_cast(u - 1)) == 0; } template constexpr T ceil2(const T u) { return static_cast(1) << clog(u); } template constexpr T floor2(const T u) { return u == 0 ? static_cast(0) : static_cast(1) << (log2p1(u) - 1); } template constexpr bool btest(const T mask, const usize ind) { return ((static_cast(mask) >> ind) & static_cast(1)); } template constexpr T bcut(const T mask, const usize ind) { return ind == 0 ? static_cast(0) : static_cast((static_cast(mask) << (64 - ind)) >> (64 - ind)); } template bool chmin(T& a, const T& b) { return (a > b ? a = b, true : false); } template bool chmax(T& a, const T& b) { return (a < b ? a = b, true : false); } constexpr unsigned int mod = 1000000007; template constexpr T inf_v = std::numeric_limits::max() / 4; template constexpr Real pi_v = Real{3.141592653589793238462643383279502884}; template T read() { T v; return std::cin >> v, v; } template std::vector read_vec(const std::size_t size) { std::vector v(size); for (auto& e : v) { std::cin >> e; } return v; } template auto read_vals() { return std::tuple...>{read()...}; } #define SHOW(...) static_cast(0) template std::vector make_v(const std::size_t size, T v) { return std::vector(size, v); } template auto make_v(const std::size_t size, Args... args) { return std::vector(size, make_v(args...)); } template class wavelet_matrix { public: using bucket_type = u64; static constexpr usize bucket_size = sizeof(bucket_type) * 8; template wavelet_matrix(const InIt first, const InIt last) : sz{static_cast(std::distance(first, last))} { std::vector b(sz); std::vector v{first, last}; for (usize d = 0; d < lg; d++) { std::vector z, o; for (usize i = 0; i < sz; i++) { b[i] = btest(v[i], lg - d - 1), (b[i] ? o : z).push_back(v[i]); } table.push_back(fid{b}), zero.push_back(z.size()); for (usize i = 0; i < z.size(); i++) { v[i] = z[i]; } for (usize i = 0; i < o.size(); i++) { v[z.size() + i] = o[i]; } } } usize less_than(usize l, usize r, const bucket_type v) const { usize ans = 0; for (usize i = 0; i < lg; i++) { if (btest(v, lg - i - 1)) { ans += table[i].zero(r) - table[i].zero(l), l = zero[i] + table[i].one(l), r = zero[i] + table[i].one(r); } else { l = table[i].zero(l), r = table[i].zero(r); } } return ans; } usize range_freq(const usize l, const usize r, const bucket_type vmin, const bucket_type vsup) const { return less_than(l, r, vsup) - less_than(l, r, vmin); } private: class fid { private: const usize sz; std::vector data; std::vector large; public: fid(const std::vector& b) : sz(b.size()), data(sz / bucket_size + 2, 0), large(sz / bucket_size + 2, 0) { for (usize i = 0; i < sz; i++) { data[i / bucket_size] |= (static_cast(b[i]) << (i % bucket_size)), large[i / bucket_size + 1] += b[i]; } for (usize i = 1; i < large.size(); i++) { large[i] += large[i - 1]; } } bool operator[](const usize n) const { return btest(data[n / bucket_size], n % bucket_size); } usize one(const usize n) const { return large[n / bucket_size] + popcount(bcut(data[n / bucket_size], n % bucket_size)); } usize zero(const usize n) const { return n - one(n); } }; const usize sz; std::vector zero; std::vector table; }; int main() { const auto n = read(); const auto a = read_vec(n); auto b = a; constexpr ll MAX = 1000000000; for (usize i = 0; i < n; i++) { b[i] += MAX; } wavelet_matrix<32> wm(b.begin(), b.end()); auto median = [&](const usize l, const usize r) -> ll { ll inf = -1, sup = 2 * MAX + 1; while (sup - inf > 1) { const ll mid = (inf + sup) / 2; const usize low = wm.less_than(l, r, mid); (low * 2 < r - l ? inf : sup) = mid; } return inf - MAX; }; ll ans = 0; for (usize k = 1; k <= n; k++) { std::vector left{0}, right{0}; for (usize l = 0; l + k <= n; l += k) { left.push_back(median(l, l + k) * (ll)k); } for (int r = (int)n; r - (int)k >= 0; r -= k) { right.push_back(median(r - k, r) * (ll)k); } const usize s = left.size() - 1; SHOW(k, left, right); for (usize i = 1; i <= s; i++) { left[i] += left[i - 1], right[i] += right[i - 1]; } for (usize i = 1; i <= s; i++) { chmax(left[i], left[i - 1]), chmax(right[i], right[i - 1]); } SHOW(k, left, right); for (usize i = 0; i <= s; i++) { chmax(ans, left[i] + right[s - i]); } } std::cout << ans << std::endl; return 0; }