input: 
  from typing import List
  
  def max_num(list: List[int]) -> int:
      """Find the maximum number in a given list of integers.
      >>> max_num([9, 2, 5, 6, 4, 1])
      9
      >>> max_num([1, 3, 7, 2, 4])
      7
      """
      max_num = list[0]
  
      for num in list:
          if num > max_num:
              max_num = num
      
      return max_num
  
output:     max_num = list[0]
  
      for num in list:
          if num > max_num:
              max_num = num
      
      return max_num