#!/bin/python3

import sys

def calculate(a,iter):
    value=0
    s=0
    for i in range(iter[1],iter[2]+1):
        s+=a[i]
    
    for i in range(iter[1],iter[2]+1):
        s=s-a[i]
        value+=s*a[i]
    return value
        
        

def largestValue(A,n,calculate=calculate):
    # Return the largest value of any of A's nonempty subarrays.
    max_so_far=0
    msf_l=msf_u=0
    meh=0
    tracker=[[0,0,0]]
    
    for i in range(n):
        meh=meh+A[i]
        if(meh<0):
            meh=0
            msf_l=i+1
        if(max_so_far<=meh):
            max_so_far=meh
            tracker[-1][0]=meh
            tracker[-1][1]=msf_l
            tracker[-1][2]=i
        #elif(max_so_far==meh):
        #    tracker.append([meh,msf_l,i])
    ans=0        
    for i in tracker:
        ans=calculate(A,i)
    return ans

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