Bạn chú ý tiêu đề nha :) https://diendan.hocmai.vn/threads/mot-bai-toan-nang-cao-mot-ti-mong-moi-nguoi-giup-do-3.761120/#post-3802651
https://diendan.hocmai.vn/threads/mot-bai-toan-nang-cao-mot-ti-mong-moi-nguoi-giup-do-3.761120/#post-3802651