text: """
  File: largest_digit.py
  Name: Fenny
  ----------------------------------
  This file recursively prints the biggest digit in
  5 different integers, 12345, 281, 6, -111, -9453
  If your implementation is correct, you should see
  5, 8, 6, 1, 9 on Console.
  """
  
  
  def main():
  	print(find_largest_digit(12345))      # 5
  	print(find_largest_digit(281))        # 8
  	print(find_largest_digit(6))          # 6
  	print(find_largest_digit(-111))       # 1
  	print(find_largest_digit(-9453))      # 9
  
  
  def find_largest_digit(n):
  	"""
  	:param n: the number to be compared
  	:return: the largest digit in the number
  	"""
  	big = 0
  	return find_largest_digit_helper(n, big)
  
  
  def find_largest_digit_helper(n, big):
  	"""
  	:param n: the number to be compared
  	:param big: the index to record the current largest digit in the number
  	:return: the largest digit in the number
  	"""
  	if n > 0:
  		if n < 10:
  			if n > big:
  				return n
  			else:
  				return big
  
  		else:
  			last_digit = n % 10
  			new_num = n // 10
  			if last_digit != 0:
  				if last_digit > big:
  					big = last_digit
  					return find_largest_digit_helper(new_num, big)
  				else:
  					return find_largest_digit_helper(new_num, big)
  	else:
  		n = n * (-1)
  		if n < 10:
  			if n > big:
  				return n
  			else:
  				return big
  
  		else:
  			last_digit = n % 10
  			new_num = n // 10
  			if last_digit != 0:
  				if last_digit > big:
  					big = last_digit
  					return find_largest_digit_helper(new_num, big)
  				else:
  					return find_largest_digit_helper(new_num, big)
  
  
  if __name__ == '__main__':
  	main()
  