The correct answer to this open question is the following.
The nation of Bosnia and Herzegovina is one of the three European countries with an alternating head of government. The other two are one Croat and one Serb.
Bosnia Herzegovina has one of the most complicated forms of government in Europe, and probably in the world. The most important political institution is the presidency. And this presidency is shared by three presidents that have periods of eight months each one. So this function of the head of the state of Bosnia and Herzegovina changes every eight months and it is occupied by obe Serb, one Bosnian, and one Croat. They also have a bicameral legislature and one head of the government that is the Chairman of the Council of Ministers. This position is appointed by the President.