# coding: utf-8
a,b=gets.chomp.split(" ").map(&:to_i);

t = a+b
h = a-b
k = a*b

if t > h then
  if t > k then
    ret = t
  else
    ret = k
  end
else
  if h > k then
    ret = h
  else
    ret = k
  end
end
print(ret)