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

Example Input: All loci have _ or two alleles.
Example Output: one

Example Input: Induction also operates early in development, even before the _ layered embryo forms.
Example Output: three

Example Input: Pertussis is highly contagious with symptoms that can linger six to _ weeks.
Example Output:
ten