I further swear (or affirm) that I do not advise, advocate or teach, and have not within the period beginning five (5) years prior to the effective date of the ordinance requiring the making of this oath or affirmation, advised, advocated or taught, the overthrow by force, violence or other unlawful means, of the Government of the United States of America or of the State of California and that I am not now and have not, within said period, been or become a member of or affiliated with any group, society, association, organization or party which advises, advocates or teaches, or has, within said period, advised, advocated or taught, the overthrow by force, violence or other unlawful means of the Government of the United States of America, or of the State of California. I further swear (or affirm) that I will not, while I am in the service of the City of Los Angeles, advise, advocate or teach, or be or become a member of or affiliated with any group, association, society, organization or party which advises, advocates or teaches, or has within said period, advised, advocated or taught, the overthrow by force, violence or other unlawful means, of the Government of the United States of America or of the State of California . . . .