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

Example Input: Pangolins walk on all _ of their stout limbs, which are adapted for digging.
Example Output: four

Example Input: Essential oils have a non-toxic, residual effect of up to five months from just _ application.
Example Output: one

Example Input: Mares can have _ or two foals.
Example Output:
one