(1) In every city of the third class, there must be a mayor and two council members. In every city of the second class, there must be a mayor and two council members. In every city of the first class having a population of less than 25,000, there must be a mayor and two council members. In every city of the first class having a population of 25,000 or more, there must be a mayor and four council members.
(2) The mayor and all council members must be elected at large.