Write regular expressions for the following language. By word, we mean an alphabetic string separated from other words by white-space, any relevant punctuation, line breaks, and so forth.

(a) The set of all strings that represent prices in the UK, i.e., the pound sign followed by a real number which has optionally two digits after the decimal point. For example, 1500 and 19.99 .

(b) The set of all strings that start at the beginning of the line with a word and finish at the end of the line with the same word.