A: https://www.luogu.com.cn/problem/U485007 B: https://www.luogu.com.cn/problem/U485011 C: https://www.luogu.com.cn/problem/U485012 D: https://www.luogu.com.cn/problem/U485015 E: https://www.luogu.com.cn/problem/U485017 F: https://www.luogu.com.cn/problem/U485018 G: https://www.luogu.com.cn/problem/U485020 H: https://www.luogu.com.cn/problem/U485021 I: https://www.luogu.com.cn/problem/U485023