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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 input(channel):
 """ Read the value of a GPIO pin. :param channel: the channel based on the numbering system you have specified (:py:attr:`GPIO.BOARD`, :py:attr:`GPIO.BCM` or :py:attr:`GPIO.SUNXI`). :returns: This will return either :py:attr:`0` / :py:attr:`GPIO.LOW` / :py:attr:`False` or :py:attr:`1` / :py:attr:`GPIO.HIGH` / :py:attr:`True`). """

    _check_configured(channel)  # Can read from a pin configured for output
    pin = get_gpio_pin(_mode, channel)
    return sysfs.input(pin)