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