n=int(input())
s=list(map(int,input().split()))
i=0;s0=0;s1=0
l=0;r=0;tl=0;tr=0
while i<n:
    if s0==0 and s[i]>0:    l=i
    s0+=s[i]
    if s1<s0:   s1=s0;r=i
    if s0<0:    s0=0
    i+=1
su=sum(s[l:r+1])
cost=0
#print(s1,l,r)
for i in range(r-l+1):
    su-=s[i+l]
    cost+=su*s[i+l]
print(cost)