n = int(input())
A = list(map(int, input().split()))
min_ = A[0]
max_ = A[0]

for a in A[1:]:
    lst = []
    for x in [min_, max_]:
        lst.append(x * a)
        lst.append(x + a)
        lst.append(x - a)
        if a != 0:
            pm = (x >= 0) ^ (a >= 0)
            tmp = abs(x) // abs(a)
            if pm:
                tmp *= -1
            lst.append(tmp)
    min_ = min(lst)
    max_ = max(lst)
print(max_)