<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def p45(msg):
 """Average static pressure. Args: msg (String):
 28 bytes hexadecimal message string Returns: int: static pressure in hPa """

    d = hex2bin(data(msg))
    if d[26] == '0':
        return None
    p = bin2int(d[27:38])    # hPa
    return p