Version using more up to date language features

[savaged]

Using top-level statements (see https://learn.microsoft.com/en-us/dotnet/csharp/whats-new/tutorials/top-level-statements) and Linq along with pattern matching (see https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals/functional/pattern-matching)

[wtlgo]

I would suggest leaving this file as it is right now and creating a separate one for C# 10, because it's quite different, to say at least.
Also, if you will, don't add unnecessary comments. Those belong here and add no value to the code itself.

[wtlgo]

I also have problems with the line

args[0].Select(...)

I understand the urge to write a one-liner, but as it's stated in the readme all programs in the repo if possible should follow a quite specific IO structure (even BF, for example) and I would love if you follow this rule in your snippet too.