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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def wv45(msg):
 """Wake vortex. Args: msg (String):
 28 bytes hexadecimal message string Returns: int: Wake vortex level. 0=NIL, 1=Light, 2=Moderate, 3=Severe """

    d = hex2bin(data(msg))
    if d[12] == '0':
        return None

    ws = bin2int(d[13:15])
    return ws