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.