'use strict'

function main(input) {
  input = input
    .trim()
    .split(' ')
    .map(v => ~~v)
  // const tmp = input[0] - input[1]
  const a = input[0]
  const b = input[1]

  console.log(Math.max(a + b, a - b, a * b))
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'))
