def remove_oclcNo_prefix(oclcNo):
    """
    removes OCLC Number prefix
    for example:
        ocm00012345 => 00012345 (8 digits numbers 1-99999999)
        ocn00012345 => 00012345 (9 digits numbers 100000000 to 999999999)
        on000123456  => 000123456 (10+ digits numbers 1000000000 and higher)
    args:
        oclcNo: str, OCLC Number
    returns:
        oclcNo: str, OCLC without any prefix
    """
    oclcNo = oclcNo.strip()
    if "ocm" in oclcNo or "ocn" in oclcNo:
        return oclcNo[3:]
    elif "on" in oclcNo:
        return oclcNo[2:]
    else:
        return oclcNo