function Main(input) {
	input = input.trim().replace(/\−/g,"-");
	var a = Number(input.split(" ")[0]);
	var b = Number(input.split(" ")[1]);
	var myList = [a+b,a-b,a*b];
	console.log(Math.max(myList[0],myList[1],myList[2]));
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));