from typing import List, Tuple, Callable, TypeVar, Optional import sys import itertools import heapq import bisect import math from collections import deque, defaultdict from functools import lru_cache, cmp_to_key input = sys.stdin.readline if __file__ != 'prog.py': sys.setrecursionlimit(10 ** 6) def readints(): return map(int, input().split()) def readlist(): return list(readints()) def readstr(): return input()[:-1] def readlist1(): return list(map(lambda x: int(x) - 1, input().split())) class BitVector: # reference: https://tiramister.net/blog/posts/bitvector/ # (reference implemention is succinct, but this implemention is not succinct.) def __init__(self, N): self.N = N self.block_num = (N + 31) >> 5 self.bit = [0] * self.block_num self.sum = [0] * self.block_num self.built = False def set(self, pos): self.bit[pos >> 5] |= 1 << (pos & 31) def build(self): assert not self.built for i in range(1, self.block_num): self.sum[i] = self.sum[i - 1] + self.popcount(self.bit[i - 1]) self.built = True def access(self, pos): """return pos-th bit""" return self.bit[pos >> 5] >> (pos & 31) & 1 def rank(self, pos): """count 1's in [0, pos) range""" assert self.built i = pos >> 5 offset = pos & 31 return self.sum[i] + self.popcount(self.bit[i] & ((1 << offset) - 1)) def select(self, num): """return minimum i that satisfies rank(i) = num""" assert self.built if num == 0: return 0 if self.rank(self.N) < num: return -1 l = -1 r = self.N while r - l > 1: c = (l + r) >> 1 if self.rank(c) >= num: r = c else: l = c return r def popcount(self, n): c = (n & 0x5555555555555555) + ((n >> 1) & 0x5555555555555555) c = (c & 0x3333333333333333) + ((c >> 2) & 0x3333333333333333) c = (c & 0x0f0f0f0f0f0f0f0f) + ((c >> 4) & 0x0f0f0f0f0f0f0f0f) c = (c & 0x00ff00ff00ff00ff) + ((c >> 8) & 0x00ff00ff00ff00ff) c = (c & 0x0000ffff0000ffff) + ((c >> 16) & 0x0000ffff0000ffff) return c class WaveletMatrix: # reference: https://miti-7.hatenablog.com/entry/2018/04/28/152259 def __init__(self, A): self.nums = sorted(set(A)) self.idx = {a: i for i, a in enumerate(self.nums)} self.A = [self.idx[a] for a in A] self.digit = (len(self.nums) - 1).bit_length() self.B = [None] * self.digit self.offset = [None] * self.digit self.start_index = {} T = self.A for k in range(self.digit)[::-1]: self.B[k] = BitVector(len(T) + 1) zeros = [] ones = [] for i, a in enumerate(T): if a >> k & 1: self.B[k].set(i) ones.append(a) else: zeros.append(a) self.B[k].build() self.offset[k] = len(zeros) T = zeros + ones for i, a in enumerate(T): self.start_index.setdefault(a, i) def access(self, i): """return i-th value""" ret = 0 cur = i for k in range(self.digit)[::-1]: if self.B[k].access(cur): ret |= (1 << k) cur = self.B[k].rank(cur) + self.offset[k] else: cur -= self.B[k].rank(cur) return self.nums[ret] def rank(self, i, x): """return the number of x's in [0, i) range""" x = self.idx.get(x) if x is None: return 0 for k in range(self.digit)[::-1]: if x >> k & 1: i = self.B[k].rank(i) + self.offset[k] else: i -= self.B[k].rank(i) return i - self.start_index[x] def quantile(self, l, r, n): """return n-th (0-indexed) smallest value in [l, r) range""" assert 0 <= n < r - l ret = 0 for k in range(self.digit)[::-1]: rank_l = self.B[k].rank(l) rank_r = self.B[k].rank(r) ones = rank_r - rank_l zeros = r - l - ones if zeros <= n: ret |= 1 << k l = rank_l + self.offset[k] r = rank_r + self.offset[k] n -= zeros else: l -= rank_l r -= rank_r return self.nums[ret] def range_freq(self, l, r, lower, upper): """return the number of values s.t. lower <= x < upper""" return self.range_freq_upper(l, r, upper) - self.range_freq_upper(l, r, lower) def prev_value(self, l, r, upper): """return maximum x s.t. x < upper in [l, r) range if exist, otherwise None""" cnt = self.range_freq_upper(l, r, upper) if cnt == 0: return None return self.quantile(l, r, cnt - 1) def next_value(self, l, r, lower): """return minimum x s.t. x >= lower in [l, r) range if exist, otherwise None""" cnt = self.range_freq_upper(l, r, lower) if cnt == r - l: return None return self.quantile(l, r, cnt) def range_freq_upper(self, l, r, upper): """return the number of values s.t. x < upper in [l, r) range""" if l >= r: return 0 if upper > self.nums[-1]: return r - l if upper <= self.nums[0]: return 0 upper = bisect.bisect_left(self.nums, upper) ret = 0 for k in range(self.digit)[::-1]: rank_l = self.B[k].rank(l) rank_r = self.B[k].rank(r) ones = rank_r - rank_l zeros = r - l - ones if upper >> k & 1: ret += zeros l = rank_l + self.offset[k] r = rank_r + self.offset[k] else: l -= rank_l r -= rank_r return ret N = int(input()) A = readlist() WM = WaveletMatrix(A) ans = 0 for k in range(1, N + 1): maxl = [0] cur = 0 acc = 0 for i in range(N // k): median = WM.quantile(cur, cur + k, (k - 1) // 2) acc += k * median maxl.append(max(maxl[-1], acc)) cur += k maxr = [0] cur = N acc = 0 for i in range(N // k): median = WM.quantile(cur - k, cur, (k - 1) // 2) acc += k * median maxr.append(max(maxr[-1], acc)) cur -= k for i in range(N // k + 1): s = maxl[i] + maxr[N // k - i] ans = max(ans, s) print(ans)