Complex sentence: The Flemish Region (Flanders) and the Walloon Region (Wallonia) each comprise five provinces; the third region, Brussels-Capital Region, is not a province, nor does it contain any.
Split into simpler sentences: The Flemish Region (Flanders) and the Walloon Region (Wallonia) each comprise five provinces. The third region, Brussels-Capital Region, is not a province, nor does it contain any.