SubmissionNumber#=%=#254 FinalPaperTitle#=%=#AIpom at SemEval-2024 Task 8: Detecting AI-produced Outputs in M4 ShortPaperTitle#=%=# NumberOfPages#=%=#6 CopyrightSigned#=%=#EArt JobTitle#==# Organization#==# Abstract#==#This paper describes AIpom, a system designed to detect a boundary between human-written and machine-generated text (SemEval-2024 Task 8, Subtask C: Human-Machine Mixed Text Detection). We propose a two-stage pipeline combining predictions from an instruction-tuned decoder-only model and encoder-only sequence taggers. AIpom is ranked second on the leaderboard while achieving a Mean Absolute Error of 15.94. Ablation studies confirm the benefits of pipelining encoder and decoder models, particularly in terms of improved performance. Author{1}{Firstname}#=%=#Alexander Author{1}{Lastname}#=%=#Shirnin Author{1}{Username}#=%=#manoftheyear Author{1}{Email}#=%=#alexamailwork@gmail.com Author{1}{Affiliation}#=%=#HSE University Author{2}{Firstname}#=%=#Nikita Author{2}{Lastname}#=%=#Andreev Author{2}{Username}#=%=#nikich28 Author{2}{Email}#=%=#nikita01n01@gmail.com Author{2}{Affiliation}#=%=#Skoltech Author{3}{Firstname}#=%=#Vladislav Author{3}{Lastname}#=%=#Mikhailov Author{3}{Username}#=%=#vmkhlv Author{3}{Email}#=%=#vmikhailovhse@gmail.com Author{3}{Affiliation}#=%=#University of Oslo Author{4}{Firstname}#=%=#Ekaterina Author{4}{Lastname}#=%=#Artemova Author{4}{Username}#=%=#artemovae Author{4}{Email}#=%=#ekaterina.l.artemova@gmail.com Author{4}{Affiliation}#=%=#Toloka.AI ========== èéáğö