input: def add_large_numbers(num1: str, num2: str) -> str:
      """ Adds two large numbers represented as strings.
      >>> add_large_numbers("111", "1337")
      '1448'
      >>> add_large_numbers("999", "1")
      '1000'
      """
output:     carry = 0
      result = []
      len1, len2 = len(num1), len(num2)
      max_len = max(len1, len2)
      
      num1 = num1.zfill(max_len)
      num2 = num2.zfill(max_len)
      
      for i in range(max_len - 1, -1, -1):
          digit1 = int(num1[i])
          digit2 = int(num2[i])
          total = digit1 + digit2 + carry
          carry = total // 10
          result.append(str(total % 10))
      
      if carry:
          result.append(str(carry))
      
      return ''.join(result[::-1])