 In contrast to republics operating under either the presidential system or the semi-presidential system, the head of state usually does not have executive powers as an executive president would (some may have 'reserve powers' or a bit more influence beyond that), because many of those powers have been granted to a head of government (usually called a prime minister).However, in a parliamentary republic with a head of state whose tenure is dependent on parliament, the head of government and head of state can form one office (as in Botswana, the Marshall Islands, Nauru, and South Africa), but the president is still selected in much the same way as the prime minister is in most Westminster systems.This usually means that they are the leader of the largest party or coalition of parties in parliament.