function main(input) {
  var splited = input.split(" ")
  var a = Number(splited[0])
  var b = Number(splited[1])
  var c = a + b
  var d = a - b
  var e = a * b
  console.log(Math.max(c, d, e))
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));