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

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

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