function Main(input) {	input = input.split("\n");
	tmp = input[0].split(" ");
	var p = parseInt(tmp[0], 10)+parseInt(tmp[1], 10);
	var m = parseInt(tmp[0], 10)-parseInt(tmp[1], 10);
	var t = parseInt(tmp[0], 10)*parseInt(tmp[1], 10);
	console.log(Math.max(p,m,t));
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));