n = int(input())
*a, = map(int,input().split())
p = n = a[0]
def sgn(x): return 1 if abs(x)==x else -1
for x in a[1:]:
    if x:
        c = abs(p)//abs(x)*sgn(p*x)
        d = abs(n)//abs(x)*sgn(n*x)
    lst = [p*x,p+x,p-x,n*x,n+x,n-x]
    p,n = max(lst), min(lst)
    if x:
        p = max(p,c,d)
        n = min(n,c,d)
print(p)