it begins to seem as long as the two year affair which is its subject 
(ROOT (S (NP (PRP it)) (VP (VBZ begins) (S (VP (TO to) (VP (VB seem) (S (ADJP (ADJP (RB as) (RB long)) (PP (IN as) (NP (NP (DT the) (NML (CD two) (NN year)) (NN affair)) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (NP (PRP$ its) (NN subject)))))))))))))))
(ROOT (S (NP (PRP )) (VP (VBZ ) (S (VP (TO ) (VP (VB ) (S (ADJP (ADJP (RB ) (RB )) (PP (IN ) (NP (NP (DT ) (NML (CD ) (NN )) (NN )) (SBAR (WHNP (WDT )) (S (VP (VBZ ) (NP (PRP$ ) (NN )))))))))))))))