var main = function(input) {
  input = input.split(' ').map(x=>parseInt(x));
  var a = input[0];
  var b = input[1];
  var array = [a+b,a-b,a*b];
  array = array.sort();
  var max = array[2];
  

    console.log(max);

    return 0; 
}

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