Learning some Haskell is very educational; it changes the way you think about programming, including daily code (much like a Lisp, Erlang, SQL, Smalltalk also do).

These examples use pretty minimal features of Haskell, mostly expressions, function definitions with argument pattern matching, and algebraic type definitions. These would take an hour or two to get acquainted with. Nothing fancy is used in the code, in particular, nothing outright monadic :)

For comparison, you can check out a Lisp version at the end. It's much longer, and Lisp (well, Racket here) is usually a very expressive language.