President of Argentina
Under the 1994 constitutional amendment, the President serves for four years, with a possibility of immediate reelection for one more term. However, unlike the President of the United States, in Argentina, a person may be reelected again after serving for two terms and staying out of office for the following term. So after serving for two consecutive periods, the president is not allowed to run for a third consecutive one, but may return for the two following elections and so on. There is no limit for a person to be a candidate if he or she does not win the elections.
President of Singapore
The President holds office for a term of six years from the date on which he or she assumes office. The office falls vacant upon the expiry of the incumbent's term or if the President is for some reason unable to complete his or her term; for example, due to death, resignation, or removal from office for misconduct or mental or physical infirmity. If the office of President becomes vacant before the incumbent's term expires, a poll for an election must be held within six months. In other cases, an election can take place any time from three months before the expiry of the incumbent's term of office.