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

Ex Input:
Most divorces take place after three to _ years of marriage.

Ex Output:
five


Ex Input:
Telescopes come in _ basic types - refractors and reflectors.

Ex Output:
two


Ex Input:
Blood flows in _ direction through the four chambers with the aid of the four heart valves.

Ex Output:

one