input: def add_large_numbers(num1: str, num2: str) -> str:
      """ Add two large numbers represented as strings.
      >>> add_large_numbers("111", "1337")
      '1448'
      >>> add_large_numbers("999", "1")
      '1000'
      """
output:     max_len = max(len(num1), len(num2))
      num1 = num1.zfill(max_len)
      num2 = num2.zfill(max_len)
      
      carry = 0
      result = []
      
      for i in range(max_len - 1, -1, -1):
          digit_sum = int(num1[i]) + int(num2[i]) + carry
          carry = digit_sum // 10
          result.append(str(digit_sum % 10))
      
      if carry:
          result.append(str(carry))
      
      return ''.join(result[::-1])