function Main(input){
  const a = input.trim().split(" ").map(Number);
  let ans = Math.max(a[0]+a[1],a[0]-a[1],a[0]*a[1]);
  if(ans==0){
  		console.log(0);
  }else{
    console.log(ans);
  }
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));