ret = 0
a, b = gets.chomp.split(" ").map(&:to_i)

plus, minus, by = a+b, a-b, a*b

if (a < 0 && b < 0) || (a > 0 && b >0)
  ret = by
elsif (a == 0 && b != 0)
  ret = plus
elsif (a != 0 && b == 0)
  ret = minus
elsif (a > 0 && b < 0)
  ret = minus
else
  ret = plus
end

p ret