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