function Main(input) {

  	tmp = input.split(" ");
    var a = parseInt(tmp[0], 10);
    var b = parseInt(tmp[1], 10);
	var ans = Math.max((a+b),(a-b),(a*b))
    if(ans === -0) ans=0
	console.log(ans);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));