# AFHKNW

Using an ordered alphabet of 26 letters, how many ways are there to choose a set of six different letters such that no two letters in the set are adjacent in the alphabet?

For instance, $$\{ISOKAY\}$$ is a valid set of six letters, but $$\{V\color{red}E\color{black}TOI\color{red}F\color{black}\}$$ is not because $$E$$ and $$F$$ are both in the set.

Note: As always, a "set" is considered unordered. Hence, $$\{ISOKAY\}$$ and $$\{YAKOSI\}$$ and $$\{AIKOSY\}$$ are considered the same set.

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