Complex sentence: The Russian Eighth Army overwhelmed the Austrian Fourth and pushed on to Lutsk, advancing forty miles beyond the starting position.Over a million of Austrians were lost, with over 500,000 men killed or taken prisoner by mid-June.
Split into simpler sentences: The Russian Eighth Army overwhelmed the Austrian Fourth and pushed on to Lutsk, advancing forty miles beyond the starting position. A large number of Austrians were lost, with over 100,000 men killed or taken prisoner by mid-June.