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

Q = [A[0]]
for a in A[1:]:
    Q2 = []
    while Q:
        x = Q.pop()
        Q2.append(x * a)
        Q2.append(x + a)
        Q2.append(x - a)
        if a > 0:
            Q2.append(x//a)
        elif a < 0:
            Q2.append(-(-x)//a)
    Q = [min(Q2),max(Q2)]

print(max(Q))