def decodeSingle(letter)
	if letter = "M"
		return 1000
	else if letter = "D"
		return 500
	else if letter =  "C"
		return 100
	else if letter = "L"
		return 50
	else if letter = "X"
		return 10
	else if letter = "V"
		return 5
	else if letter = "I"
		return 1
	else
		return 0
	end
end

def decode(roman)
	result = 0
	uRoman = roman.toUpperCase()
	
	for (i = 0) (i < len(uRoman) - 1) (i += 1)
		if decodeSingle(uRoman[i]) < decodeSingle(uRoman[i + 1])
			result -= decodeSingle(uRoman[i])
		else
			result += decodeSingle(uRoman[i])
		end
	end
	
	result += decodeSingle(uRoman[len(uRoman) - 1])
	return result
end

println decode("MCMXC")
println decode("MMVIII")
println decode("MDCLXVI")