function Main(input){
	input1 = input.split(' ');
    input2 = input1.map(input1=>parseInt(input1,10));
    a = input2[0] + input2[1];
    b = input2[0] - input2[1];
    c = input2[0] * input2[1];

    console.log(Math.max(a, b, c)+0);
}
 
Main(require("fs").readFileSync("/dev/stdin","utf8"));