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

Ex Input:
Titanium is found in column _ along with chemically similar zirconium, hafnium, and thorium.

Ex Output:
four


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

Ex Output:
two


Ex Input:
Most young men become monks for at least _ months to a year.

Ex Output:

six