randomL lst gen =
  let len         = length lst
      (idx, gen') = randomR (0, len-1) gen
  in  (lst !! idx, gen')
randomL lst gen =
  let len         = length lst
      (idx, gen') = randomR (0, len-1) gen
  in  (lst !! idx, gen')
randomL lst gen =
  let len         = length lst
      (idx, gen') = randomR (0, len-1) gen
  in  (lst !! idx, gen')