International Math Olympiad, IMO 2023, Problem 5

I solve problem 5 from the 2023 International Math Olympiad. IMO Problems: https://www.youtube.com/playlist?list=PLvt4fmEPBjqrMFbipuG0ounTg0BivlWQ2 Putnam Problems: https://www.youtube.com/playlist?list=PLvt4fmEPBjqrtO0SCh43ob4mgWyh6amBm IMO 2023: Problem 1: https://youtu.be/OC_1FPv7ecM Problem 2: https://youtu.be/2CIEhZKMVbQ Problem 4: https://youtu.be/0aVWanMl2aA Problem 5: https://youtu.be/bTUu2G2T-Is IMO 2022: Problem 2: https://youtu.be/c0L3P7_aCFc IMO 2021: Problem 1: https://youtu.be/BlNDOpUnNIQ A1: https://youtu.be/RS080HyMZLQ A2: https://youtu.be/9z5-5wJvero A3: https://youtu.be/U3eMXwa-iWU C1: https://youtu.be/bzOTw0U5UDs IMO 2020: Problem 2: https://youtu.be/CBULrz-ZAOE IMO 2019: N2: https://youtu.be/DvXovQEB-wc IMO 1961: Problem 1: https://youtu.be/ix0LshlSUoQ