The Sudetes are a geologically diverse mountain range that stretches for 280 kilometres  from the Lusatian Highlands in the west and to the Moravian Gate in the east. They are topographically divided into Western, Central and Eastern Sudetes. The Lower Silesian section of the Sudetes comprises the Jizera Mountains , where the tripoint with Upper Lusatia and Bohemia is located near the Smrk summit, along with the adjacent Karkonosze Krkonoše  ; Rudawy Janowickie ; Owl Mountains ; Stone Mountains ; Wałbrzych Mountains  and the Kaczawskie Mountains  with Ostrzyca, 501 m or 1,644 ft - they surround the Jelenia Góra valley, 420-450 m or 1,380-1,480 ft; Ślęża Massif , massive of Orlické hory, Králický Sněžník south of historical Kladsko Polish: Klodzsko), Rychlebské hory and Jeseníky   .. How many m are the Wałbrzych Mountains and the Kaczawskie Mountains with Ostrzyca compared to the Jelenia Góra valley?