"use strict";
main(require("fs").readFileSync("/dev/stdin", "UTF-8"));

function main(input) {
  input = input
    .split("\n")[0]
    .split(" ")
    .map(n => Number(n));
  let max = input[0] + input[1];
  if (max < input[0] - input[1]) {
    max = input[0] - input[1];
  }
  if (max < input[0] * input[1]) {
    max = input[0] * input[1];
  }
  console.log(max);
}
