Input (grade 12): S.T.A.L.K.E.R.: Shadow of Chernobyl is a first-person shooter computer game by the Ukrainian developer GSC Game World, published in 2007.
Output (grade 11): S.T.A.L.K.E.R.: Shadow of Chernobyl, previously known as S.T.A.L.K.E.R.: Oblivion Lost, is a post-apocalyptic first-person shooter computer game by Ukrainian developer GSC Game World.