#!/bin/python3

import sys

def kadane(a,size):
 
    max_so_far = -1001
    max_ending_here = 0
    start = 0
    end = 0
    s = 0
 
    for i in range(0,size):
 
        max_ending_here += a[i]
 
        if max_so_far < max_ending_here:
            max_so_far = max_ending_here
            start = s
            end = i
 
        if max_ending_here < 0:
            max_ending_here = 0
            s = i+1
    
    a=A[start:end+1]
    return a

def largestValue(A):
    # Return the largest value of any of A's nonempty subarrays.
    sumn=0
    while(len(A)>0):
        x=A.pop()
        sumn+=(x*sum(A))
    return sumn
        

if __name__ == "__main__":
    n = int(input().strip())
    A = list(map(int, input().strip().split(' ')))
    a = list()
    a=kadane(A,n)
    result = largestValue(a)
    print(result)