Complex sentence: Nevertheless, some hillwalkers attempt to climb as many Marilyns as possible as a form of peak bagging; as of 2005, no-one has completed the list, however three people are only five short.
Split into simpler sentences: Nevertheless, some hillwalkers attempt to climb as many Marilyns as possible as a form of peak bagging. As of 2005, no one has completed the list; however, three people are only five short.