The editions on AOJ and yukicoder are still `2015`. - [現在の各プラットフォームで使えるRust](https://github.com/rust-lang-ja/atcoder-rust-resources/wiki/Since-1.15.1#%E7%8F%BE%E5%9C%A8%E3%81%AE%E5%90%84%E3%83%97%E3%83%A9%E3%83%83%E3%83%88%E3%83%95%E3%82%A9%E3%83%BC%E3%83%A0%E3%81%A7%E4%BD%BF%E3%81%88%E3%82%8Brust) - yosupo06/library-checker-judge#145
