function main(A,B){
  var result = [];
  Array.prototype.push.call(result,A + B,A - B, A * B);
  console.log(Math.max.call({},...result));  
}

const input = require('fs').readFileSync('/dev/stdin','utf8').split(' ');
const A = Number(input[0]);
const B = Number(input[1]);

main(A,B);