I wanted to make a number generator using this chrono::steady_clock::now ().time_since_epoch ().count ();, but VS gives these 3 errors: "C2653 chrono: is not a class or namespace name", "C3861 now: id not found", "C2737 : the object needs to be initialized ". And in sending the code to codeforces everything works with the GNU G++20 compiler.

Quite a few people have written off problems E, D and C. I think this is unfair, and I urge everyone not to cheat!!! Rating is not the most important thing on codeforces, if you have risen in the rating dishonestly, then you will not rise above the person who merges codes in this way!!! If you find similar ones, write the identification codes here. I'm sorry for my poor English. Here are some decommissioned codes: