it doesn't look like their prelude has any stdout printing functions, so it's probably easiest to test your code in a repl. you can check what functions they do

it doesn't look like their prelude has any stdout printing functions, so it's probably easiest to test your code in a repl. you can check what functions they do give you by looking at the stuff before the "where" here: https://github.com/mightybyte/monad-challenges/blob/gh-pages/src/MCPrelude.hs https://github.com/mightybyte/monad-challenges/blob/gh-pages... as for verifying your results, they give you the product of the 5 numbers at the bottom of the page (since you're starting from a predetermined seed, the 5 numbers you generate are known)