'use strict'

function main(input) {
  input = input.split(' ').map(v => ~~v)

  let ans = input[0] + input[1]
  ans = Math.max(ans, input[0] - input[1])
  ans = Math.max(ans, input[0] * input[1])

  console.log(ans)
}
main(require("fs").readFileSync("/dev/stdin", "utf8"));