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