// 2019/05/12
// AtCoder Beginner Contest 098 - A
// (stdin: type Ctrl + D after input)

"use strict";
 
function Main(in_input){
    // Modify Input
    var in_lines = in_input.split("\n");
    var in_line1 = in_lines[0].split(" ");
    var a = parseInt(in_line1[0], 10);
    var b = parseInt(in_line1[1], 10);

    // Calc Answer
    var c_max = a + b;
    var mi = a - b;
    var ti = a * b;

    if(c_max < mi){
        c_max = mi;
    }
    if(c_max < ti){
        c_max = ti;
    }

    // Output
    console.log(c_max);
}
 
Main(require("fs").readFileSync("/dev/stdin", "utf8"));