input: Write a python function to find the mode of a list of numbers.
  assert find_mode([1, 2, 2, 3, 3, 3, 4]) == 3
  assert find_mode([5, 5, 5, 2, 2, 2, 2, 3, 3, 4]) == 2
  assert find_mode([10, 20, 20, 30, 30, 30, 40, 40, 40, 40]) == 40
output: def find_mode(numbers):
      from collections import Counter
      count = Counter(numbers)
      max_count = max(count.values())
      mode = [num for num, freq in count.items() if freq == max_count]
      return mode[0]