function Main(input){
	input = input.split(' ');
    input = input.map(input=>parseInt(input,10));
    a = input[0] + input[1];
    b = input[0] - input[1];
    c = input[0] * input[1];
  
    //console.log(a);
    //console.log(b);
    //console.log(c);
    console.log(Math.max.apply(null, [a, b, c]));
}
 
Main(require("fs").readFileSync("/dev/stdin","utf8"));