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

Example Input: Ticks mature in _ stages, moving from egg to larva and nymph to adult.
Example Output: four

Example Input: Wood has _ dimensions, width, length, thickness.
Example Output: three

Example Input: Sound waves travel through the air in a similar manner, but in all _ dimensions.
Example Output:
three