n = gets.to_i
a = gets.split.map &:to_r
mi = ma = a[0]
a[1..-1].each do |r|
  _mi = mi
  _ma = ma
  [mi, ma].each do |m|
    ar = [m+r, m-r, m*r]
    ar << (m/r) if r != 0
    _mi = ar.min
    _ma = ar.max
  end
  mi = _mi
  ma = _ma
end
puts ma.to_i