Write the shortest regular expression that matches all the green words and none of the red words. Fewer characters means a better score.
. any character[abc] character class[^abc] negated class[a-z] range^ start of string$ end of string\b word boundary* 0 or more+ 1 or more? 0 or 1{n} exactly n{n,m} n to m times(abc) groupa|b alternation\d digit [0-9]\w word char [a-zA-Z0-9_]\s whitespace\D non-digit\W non-word char\S non-whitespace(?:) non-capturing group