Go-go dancing 1960s-era clubgoers wore miniskirts and knee-high, high-heeled boots, which eventually came to be called go-go boots. Night club promoters in the mid‑1960s then conceived the idea of hiring women dressed in these outfits to entertain patrons. The term "go-go" derives from the phrase "go-go-go" for a high-energy person, and was influenced by the French expression "à gogo", meaning "in abundance, galore", which is in turn derived from the ancient French word "la gogue" for "joy, happiness". On 19 June 1964, Carol Doda began go-go dancing topless at the Condor Club on Broadway and Columbus in the North Beach neighborhood of
Square-free word Square-free word In combinatorics, a square-free word is a word (a sequence of characters) that does not contain any subword twice in a row. Thus a square-free word is one that avoids the pattern "XX". Over a two-letter alphabet {"a, b"} the only square-free words are the empty word and "a", "b", "ab", "ba", "aba", and "bab". However, there exist infinite square-free words in any alphabet with three or more symbols, as proved by Axel Thue. One example of an infinite square-free word over an alphabet of size 3 is the word over the alphabet {0,±1} obtained by taking the