module Exercise_6 where

import Data.Ratio

{-WETT-}
traceFractran :: [Rational] -> Integer -> [Integer]
traceFractran fs n = 
  let prods = [numerator (n%1 * f) | f <- fs, denominator (n%1 * f) == 1] 
  in if null prods then [n] else n : traceFractran fs (head prods)
{-TTEW-}