Complex sentence: Vladimir Putin has served three terms as President of Russia (2000 to 2004,2004 to 2008 and 2012 to present) and was acting president from 1999--2000, succeeding Boris Yeltsin after Yeltsin's early retirement.
Split into simpler sentences: Vladimir Putin has served three terms as President of Russia: 2000 to 2004,2004 to 2008,2012 to present. He was acting president from 1999--2000, succeeding Boris Yeltsin after Yeltsin's early retirement.