CREATE TABLE "region" (
"Region_ID" int,
"Region_name" text,
"Date" text,
"Label" text,
"Format" text,
"Catalogue" text,
PRIMARY KEY ("Region_ID")
)

CREATE TABLE "party" (
"Party_ID" int,
"Minister" text,
"Took_office" text,
"Left_office" text,
"Region_ID" int,
"Party_name" text,
PRIMARY KEY ("Party_ID"),
FOREIGN KEY (`Region_ID`) REFERENCES `region`(`Region_ID`)
)

CREATE TABLE "member" (
"Member_ID" int,
"Member_Name" text,
"Party_ID" text,
"In_office" text,
PRIMARY KEY ("Member_ID"),
FOREIGN KEY (`Party_ID`) REFERENCES `party`(`Party_ID`)
)

CREATE TABLE "party_events" (
"Event_ID" int,
"Event_Name" text,
"Party_ID" int,
"Member_in_charge_ID" int,
PRIMARY KEY ("Event_ID"),
FOREIGN KEY (`Party_ID`) REFERENCES `party`(`Party_ID`),
FOREIGN KEY (`Member_in_charge_ID`) REFERENCES `member`(`Member_ID`)
)
SELECT T2.party_name FROM party_events AS T1 JOIN party AS T2 ON T1.party_id  =  T2.party_id GROUP BY T1.party_id HAVING count(*)  >=  2
What are the names of parties with at least 2 events?