Complex sentence: The highest mountain in the Eastern Alps is Piz Bernina (4052 m) in Switzerland, followed by the Ortler (3905 m) in Italy/South Tyrol and then Großglockner (3798 m) in Austria.
Split into simpler sentences: The highest mountain in the Eastern Alps is Piz Bernina (4052 m) in Switzerland. Excepting other peaks in the Bernina range, the next highest is the Ortler (3905 m) in Italy/South Tyrol and then the Großglockner (3798 m) in Austria.