function main (arg) {
	arg = arg.trim().split(' ');
  	var a = Number(arg[0]), b = Number(arg[1]), out = [];
  	out.push(a+b, a-b, a*b);
  	out = Math.max(...out);
  	console.log(out);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));