From the challenge:

The W4C (World Wide Wireless Web Consortium) has just published the specification of SML/NG (Simple Markup Language -- New Generation), a simplified version of XXHTML designed for the new generation of hypertext rendering micro-devices, running on hardware with reduced computational capacity such as wristtop computers, thumbnail-worn PDAs, and internet-enabled ice boxes.

The programming task is to design and implement an optimiser for SML/NG that will simplify the source documents and reduce their size.

You must write a program to optimise SML/NG documents. Your program will be given a correct SML/NG document on its standard input, and it must output (on stdout) an equivalent document that is as small as possible. The size of a document is simply defined as its length in bytes.