import re


def _strip_ken_suffix(name):
    """
    >>> _strip_ken_suffix('Akita ken')
    'Akita'
    >>> _strip_ken_suffix('Akita-ken')
    'Akita'
    >>> _strip_ken_suffix('Akita Prefecture')
    'Akita'
    """
    return re.sub(r'[- ](ken|prefecture)', '', name, flags=re.IGNORECASE)