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