from sortedcontainers import SortedList
from itertools import accumulate

N=int(input())
A=list(map(int, input().split()))
to_right=list(accumulate(A))
to_left=list(accumulate(A[::-1]))[::-1]

if N == 2:
    print(A[0]*A[1])
    exit()

left=SortedList([])
right=SortedList([])

mem1=[A[0]]
mem2=[A[0]]
rmem1=[A[-1]]
rmem2=[A[-1]]

left.add(A[0])
right.add(A[-1])
for i in range(1,N-1):
    mem1.append(max(to_right[i]-left[0], to_right[i]))
    mem2.append(min(to_right[i]-left[-1],to_right[i]))
    left.add(to_right[i])

for i in range(-2,-N,-1):
    rmem1.append(max(to_left[i]-right[0], to_left[i]))
    rmem2.append(min(to_left[i]-right[-1], to_left[i]))
    right.add(to_left[i])

to_rightmax = list(accumulate(mem1, lambda x,y: max(x,y))) 
to_rightmin = list(accumulate(mem2, lambda x,y: min(x,y)))
to_leftmax = list(accumulate(rmem1, lambda x,y: max(x,y)))[::-1]
to_leftmin = list(accumulate(rmem2, lambda x,y: min(x,y)))[::-1]

ans=0
for i in range(N-1):
    ans = max(ans, to_rightmax[i]*to_leftmax[i])
    ans = max(ans, to_rightmax[i]*to_leftmin[i])
    ans = max(ans, to_rightmin[i]*to_leftmax[i])
    ans = max(ans, to_rightmin[i]*to_leftmin[i])

print(ans)