numeralDict = {"I": 1, "V": 5, "X": 10} #Add some more numerals here if you want bigger numbers

class numeral:
	def __init__(self, numeralString):
		self.value = [""]
		lastValue = 0
		for letter in numeralString:
			letterValue = numeralDict[letter]
			if letterValue < lastValue:
				self.value.append(letter)
			else:
				self.value[-1] += letter
			lastValue = letterValue

	def addOne(self):
		if self.value[-1] == "IV":
			self.value[-1] = "V"
		elif self.value[-1] == "III":
			self.value[-1] = "IV"
		else:
			self.value[-1] += "I"
		return self

	def __repr__(self):
		return " ".join(self.value)

#Test
nums = [
	numeral("XXIV"),
	numeral("XVII"),
	numeral("XIII"),
	numeral("X"),
]

print(nums)
print([x.addOne() for x in nums])