This is the well known game where the aim of the player is to guess a word by consecutive choices of the letters that compose the word itself.

In this case, the words are names of European cities as reported by Geonames but in which, for sake of simplicity, any blanks and diacritical marks are eliminated. For example Sant'Agata dei Goti is written as santagatadeigoti The distinction between upper and lower case is irrelevant.