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

Example Input: Frozen grafts can have a shelf life of up to _ years.
Example Output: five

Example Input: Death usually occurs by five to _ years of life due to pneumonia or other infections.
Example Output: eight

Example Input: Aptian salt forms _ low diapirs separated by a long, flat weld.
Example Output:
three