def getAddressClass(binaryString):
	""" This will calculate the address class of the IP address based on bits of binary string
			A: 0...
			B: 10..
			C: 110.
			D: 1110
			E: 1111
	"""
	
	# initialize variable
	addressClass=""
	
	# troubleshooting
	# print(binaryString)
	
	# determine the address class
	if binaryString[0] == "0":
		addressClass =  "A"
	elif binaryString[0:2] == "10":
		addressClass =  "B"
	elif binaryString[0:3] == "110":
		addressClass =  "C"
	elif binaryString[0:4] == "1110":
		addressClass =  "D"
	elif binaryString[0:4] == "1111":
		addressClass = "E"
	
	return addressClass