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