n = gets.to_i
a = gets.split.map(&:to_i)

cur = a[0]
for i in 1 ... n
  op = a[i]
  ma = -1000000
  if op != 0
    c = cur
    o = op
    t = 0
    if c < 0
      t = 1 - t
      c = -c
    end
    if o < 0
      t = 1 - t
      o = -o
    end
    ma = [ma, (-1) ** t * c / o].max
  end
  ma = [ma, cur * op].max
  ma = [ma, cur + op].max
  ma = [ma, cur - op].max
  cur = ma
end
puts cur