import sys

while True:
    print("\nWhat would you like to convert? \nPress 1 for centimer/inch conversion, "
          "\n2 for meter/feet conversion, \n3 for kilogram/pound conversion."
          "\nAt any time, type 'end' to end the program.")

    x = input("> ")

    if x == "1":
        print("Press 1 for inches to centimers and 2 for centimers to inches.")
        y = input("> ")
        if y == "1":
            cm = 2.54
            inch = int(input("Enter a number of inches: "))
            print("\n%s inches is equal to %s centimeters" % (inch, inch*cm) + ".")
        if y == "2":
            inches = 0.3937
            centimeters = int(input("Enter a number of centimeters: "))
            print("\n%s centimeters is equal to %s inches" % (centimeters, centimeters*inches) + ".")


    if x == "2":
        print("Press 1 for feet to meters and 2 for meters to feet.")
        z = input("> ")
        if z == "1":
            m = 0.3048
            ft = int(input("Enter a number of feet: "))
            print("\n%s feet is equal to %s meters" % (ft, ft*m) + ".")
        if z == "2":
            feet = 3.2808
            meters = int(input("Enter a number of meters: "))
            print("\n%s meters is equal to %s feet" % (meters, meters*feet) + ".")


    if x == "3":
        print("Press 1 for pounds to kilograms and 2 for kilograms to pounds.")
        b = input("> ")
        if b == "1":
            kg = 0.4536
            lbs = int(input("Enter a number of pounds: "))
            print("\n%s pounds is equal to %s kilograms" % (lbs, lbs*kg) + ".")
        if b == "2":
            pounds = 2.205
            kilograms = int(input("Enter a number of kilograms: "))
            print("\n%s kilograms is equal to %s pounds" % (kilograms, pounds*kilograms) + ".")


    if x.lower() == "end":
        print("Goodbye!") + sys.exit(0)