def resolve_json_kind(data, _sin=False):
    """
    Resolve if json is `std` or `community`.

    std - standard physical parameters (M1, M2)
    community - astro community parameters (q, a)

    :param data: Dict; json like
    :param _sin: bool; if False, looking for `semi_major_axis` in given JSON, otherwise looking for `asini`
    :return: str; `std` or `community`
    """
    lookup = 'asini' if _sin else 'semi_major_axis'
    m1, m2 = data['primary'].get('mass'), data['secondary'].get('mass')
    q, a = data['system'].get('mass_ratio'), data['system'].get(lookup)
    if m1 and m2:
        return 'std'
    if q and a:
        return 'community'
    raise LookupError('It seems your JSON is invalid.')
