var lines = [];
var reader = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});
reader.on('line', function(line) {
  lines.push(line);
});
reader.on('close', function() {
  for(var i = 0; i < lines.length; i++) {
    arr = lines[i].split(' ');
    a = Number(arr[0]);
    b = Number(arr[1]);
    ab = [ a+b, a-b, a*b ].sort();
    console.log(ab.pop());
  }
});