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

Example Input: Cleavage is imperfect in _ directions, prismatically.
Example Output: two

Example Input: Electric vehicles have _ tailpipe emissions.
Example Output: zero

Example Input: Mellow cheese ages _ to seven months and has rich, full flavors with soft to semisoft textures.
Example Output:
four