In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.

Ex Input:
Some school boards have _ teacher-librarians at all.

Ex Output:
no


Ex Input:
Planaria has rudimentary eyes which produce _ images but detect direction.

Ex Output:
no


Ex Input:
Water is the only natural substance which exists in all _ states of matter in nature.

Ex Output:

three