Two candidates receiving the highest number of votes for any given office at the primary nominating election shall be candidates, and the only candidates for such office whose names shall be printed upon the ballot to be used at the next general municipal election; provided, that where more than one office of the same kind is to be filled, the candidates therefor, equaling in number twice the number of such offices, who receive the highest number of votes at the primary nominating election, shall be the candidates and the only candidates for such offices whose names shall be printed upon the ballot to be used at such general election.