function Main(input){
  let xs = input.split(' ').map(v => Number(v));
  a = xs[0] + xs[1];
  b = xs[0] - xs[1];
  c = xs[0] * xs[1];

  console.log(Math.max(a, b, c));
}

Main(require("fs").readFileSync("/dev/stdin","utf8"));