<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def pump_command(self, param):
 """ Models "LNP Pump Commands" functionality of device. Switches between automatic or manual pump mode, and adjusts speed when in manual mode. :param param: 'a0' for auto, 'm0' for manual, [0-N] for speed. :return: """

        lookup = [c for c in "0123456789:;<=>?@ABCDEFGHIJKLMN"]

        if param == "a0":
            self.device.pump_manual_mode = False
        elif param == "m0":
            self.device.pump_manual_mode = True
        elif param in lookup:
            self.device.manual_target_speed = lookup.index(param)

        return ""