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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 get_vm_size(vm_):
    r'''
    Returns the VM's size.

    vm\_
        The VM to get the size for.
    '''
    vm_size = config.get_cloud_config_value('size', vm_, __opts__)
    ram = avail_sizes()[vm_size]['RAM']

    if vm_size.startswith('Linode'):
        vm_size = vm_size.replace('Linode ', '')

    if ram == int(vm_size):
        return ram
    else:
        raise SaltCloudNotFound(
            'The specified size, {0}, could not be found.'.format(vm_size)
        )