Like many other countries, Korea has made law school an undergraduate institution. Most universities and colleges also have graduate law programs. Admission to the bar requires completion of the 2-year course offered by the government-run Judicial Research and Training Center, following passage of the bar exam. The judiciary system rests on the principle of judicial independence and includes three levels of courts. Judges must be prosecutors or attorneys or have completed 2 years of training at the Judicial Research and Training Institute after passing the national judicial examination. Judicial tenure is 10 years, and consecutive terms are possible. They must retire at specified ages. The prosecutor's office is part of the executive component of government. Public prosecutors have the sole but discretionary power to decide whether or not a suspect should be prosecuted.