def get_mnsp_index(data) -> list:
    """Get MNSP index"""

    mnsps = (data.get('NEMSPDCaseFile').get('NemSpdInputs')
             .get('PeriodCollection').get('Period')
             .get('InterconnectorPeriodCollection')
             .get('InterconnectorPeriod'))

    return [i['@InterconnectorID'] for i in mnsps if i['@MNSP'] == '1']