input: Write a function to find the maximum number from a list of non-negative integers. If the list is empty, return 0.
  
  assert find_max([1, 3, 12, 5, 8, 10]) == 12
  assert find_max([0, 0, 0, 0]) == 0
  assert find_max([23, 45, 67, 89]) == 89
  assert find_max([]) == 0
  assert find_max([1]) == 1
output: def find_max(lst):
      if not lst:
          return 0
      return max(lst)