"use strict";
const main = arg => {
  let Nums = arg.split(" ").map(x=>x*1);
  let ans = 0;
  ans = Math.max(Nums[0]*Nums[1],Nums[0]+Nums[1],Nums[0]-Nums[1])
  console.log(ans);
}

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