'use strict'

function main(s) {

  s = s.split('\n')[0].split(' ');
  const A = Number(s[0]);
  const B = Number(s[1]);
  const plus = A + B;
  const minus = A - B;
  const multi = A * B;
  let max = Math.max(...[plus, minus, multi]);
  if (max === +0 || max === -0) max = 0;
  console.log(max);

}

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