object Main {
  def main(args:Array[String]) = {
    val in = readLine.split(" ").map(_.toInt)
    val a = in(0)
    val b = in(1)
    
    val p = a + b
    val m = a - b
    val t = a * b
    
    val r1 = if(p > m) p else m
    val r2 = if(r1 > t) r1 else t
    println(r2)
  }
}