input: Write a python function to find the most popular element in a list using the Counter class from the collections module.
  assert most_popular([1, 5, 9, 1, 4, 5, 9]) == 1
  assert most_popular([4, 4, 4, 2, 2, 3, 3, 1]) == 4
  assert most_popular([10, 20, 10, 10, 30, 20, 30, 30, 30]) == 30
output: def most_popular(lst):
      from collections import Counter
      counter = Counter(lst)
      return counter.most_common(1)[0][0]