#!/bin/python3

from sys import maxsize

def largestValue(A):
    max_so_far = -maxsize - 1
    max_ending_here = 0
    start = 0
    end = 0
    s = 0
    size = len(A)
 
    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
    z = A[start:end+1]

    x = []
    c = 0
    y = 0
    n = sum(z)
    # Return the largest value of any of A's nonempty subarrays.
    for i in range(0,len(z)-1):
        c = c + z[i]
        b = n - c
        x.append(b)
    for j in range(0,len(z)-1):
        y = y + z[j]*x[j]
    return(y)
if __name__ == "__main__":
    n = int(input().strip())
    A = list(map(int, input().strip().split(' ')))
    result = largestValue(A)
    print(result)