input: Write a python function to find the n-th most frequent element in a list.
  assert find_nth_most_frequent(1, [1, 2, 3, 2, 3, 3, 4]) == 3
  assert find_nth_most_frequent(2, [1, 2, 3, 2, 3, 3, 4]) == 2
  assert find_nth_most_frequent(3, [1, 2, 3, 2, 3, 3, 4]) == 1
  assert find_nth_most_frequent(1, ['apple', 'banana', 'apple', 'orange', 'banana', 'apple']) == 'apple'
  assert find_nth_most_frequent(2, ['apple', 'banana', 'apple', 'orange', 'banana', 'apple']) == 'banana'
output: def find_nth_most_frequent(n, lst):
      from collections import Counter
      freq = Counter(lst)
      sorted_freq = sorted(freq.items(), key=lambda x: x[1], reverse=True)
      return sorted_freq[n-1][0]