convert("one hundred five");  // "105"
convert("six hundred and fifty three");  // "653"
convert("zero zero one two three");  // "123"
convert("twelve o three");  // "1203"
convert("thirteen zero nine");  // "1309"
convert("fifteen sixteen");  // "1516"
convert("fourteen ninety two");  // "1492"
convert("nineteen ten");  // "1910"
convert("twenty twenty");  // "2020" <---- ugh!
convert("twenty twenty one");  // "2021"  <---- ehhh...
convert("twenty twenty two");  // "2022"  <---- let's hope!
convert("four five two three eight");  // "45238"
convert("sixteen thousand three eighty four");  // "16384"
convert("seven billion six hundred eighty-one million"); // "7681000000"
convert("twenty three trillion and nine");  // "23000000000009"
convert("four billion two hundred nine thousand");  // "4000209000"
convert("nine hundred ninety nine quadrillion nine ninety nine trillion nine hundred and ninety nine billion nine ninety-nine million nine hundred ninety-nine thousand nine ninety nine");  // "999999999999999999"
convert("one two three four five six seven eight nine eight seven six five four three two one two three four five"); // "123456789876543212345"

convert("forty two point zero");  // "42.0"
convert("three point one four one five nine two six");  // "3.1415926"
convert("point");  // "0.0"
convert("four point zero o o o zero");  // "4.00000"

convert("sixty five thousand five thirty six",",");  // "65,536"
convert("four billion two hundred nine thousand",",");  // "4,000,209,000"
convert("forty two",",");  // "42"
convert("twenty one twenty three",",");  // "2,123"
convert("one two three four five six seven eight nine eight seven six five four three two one two three four five",","); // "123456,789,876,543,212,345" <---- not a mistake, quadrillion is the highest supported "place"