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

Example Input: Acute sinusitis is any infectious process in the sinus lasting from one day to _ weeks.
Example Output: three

Example Input: Polymorphism occurs in all species and the mandibles bear _ teeth.
Example Output: four

Example Input: Stitches go through the spine linings around _ threads at head and tail.
Example Output:
three