N = int(input())

A = list(map(int,input().split()))

ans = A[0]*A[1]

for loop in range(2):

    B = [0] + A
    for i in range(N):
        B[i+1] += B[i]

    L = []
        
    sml = float("inf")
    nmaxL = float("-inf")
    for i in range(N+1):
        nmaxL = max(nmaxL , B[i]-sml)
        L.append(nmaxL)
        sml = min(sml , B[i])

    C = [0] + list(reversed(A))
    for i in range(N):
        C[i+1] += C[i]
    R = []
    sml = float("inf")
    nmaxL = float("-inf")
    for i in range(N+1):
        nmaxL = max(nmaxL , C[i]-sml)
        R.append(nmaxL)
        sml = min(sml , C[i])

    L = L[1:]
    R = R[1:]
    R.reverse()

    for i in range(len(L)-1):
        ans = max(ans, L[i] * R[i+1])

    for i in range(N):
        A[i] *= -1

print (ans)