( ( At 8,611 ) ( ( ( ( ( m K2 ) , ) ( ( the ( second ( highest mountain ) ) ) ( in ( the world ) ) ) ) , ) ( ( is ( difficult ( by ( any route ) ) ) ) . ) ) )
(ROOT (S (PP (IN At) (NP (CD 8,611))) (NP (NP (NNP m) (NNP K2)) (, ,) (NP (NP (DT the) (JJ second) (JJS highest) (NN mountain)) (PP (IN in) (NP (DT the) (NN world)))) (, ,)) (VP (VBZ is) (ADJP (JJ difficult) (PP (IN by) (NP (DT any) (NN route))))) (. .)))
At 8,611m K2, the second highest mountain in the world, is difficult by any route.
(ROOT (S (NP (NNP K2)) (VP (VBZ is) (NP (NP (DT the) (JJ second) (JJS highest) (NN mountain)) (PP (IN in) (NP (DT the) (NN world)))) (, ,) (PP (IN at) (NP (IN over) (CD 28,000) (NNS feet)))) (. .)))