function main(inp) {
  const args = inp.split(' ');
  const a = Number(args[0]);
  const b = Number(args[1]);
  if(isNaN(a) || isNaN(b))throw new Error("nan");
  var m = a + b;
  if (a - b > m) m = a - b;
  if (a * b > m) m = a * b;
  console.log(m);
}
main(require('fs').readFileSync('/dev/stdin', 'UTF-8'));