'use strict'
function Main(input) {
  const inputArray = input.split(' ').map(n => Number(n));
  const a = inputArray[0];
  const b = inputArray[1];
  const plus = a + b;
  const minus = a - b;
  const times = a * b;
  
  console.log(Math.max(plus, minus, times));
}

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