function main(lines) {
  const lin = lines[0].split(" ");
  const a = Number(lin[0]);
  const b = Number(lin[1]);
  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'));