Read this: Josip Broz was born to a Croat father and Slovene mother in the village of Kumrovec, Croatia. Drafted into military service, he distinguished himself, becoming the youngest Sergeant Major in the Austro-Hungarian Army of that time. After being seriously wounded and captured by the Imperial Russians during World War I, Josip was sent to a work camp in the Ural Mountains. He participated in the October Revolution, and later joined a Red Guard unit in Omsk. Upon his return home, Broz found himself in the newly established Kingdom of Yugoslavia, where he joined the Communist Party of Yugoslavia (KPJ).

What party in Yugoslavia did he join?
What is the answer? (If it cannot be answered, return "unanswerable")
Communist Party