function Main(input){
var A = input.split(" ")[0];
var B = input.split(" ")[1];
var add = new Number(A) + new Number(B);
var dev = A - B;
var mul = A * B;
if(add >= dev && add >= mul){
  console.log(add);
}else if(dev >= add && dev >= mul){
  console.log(dev);
}else{
  console.log(mul);
}
}
  Main(require('fs').readFileSync('/dev/stdin','utf8'));