Each poster posts a "word" that finishes the word of the previous poster.
Example:
Poster A: Space
Poster B: Space Station
<creating "Space Station">
Poster B has now started a new word with "Station"
Poster C adds another word to make "station" a two word noun: Station Wagon.
<creating "Station Wagon">
Etc.
The first word will be easy. SNOW
The next poster will write "Snow ______" with the ______ being a word that finishes the noun.