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

Ex Input:
Birds bitten by infected mosquitoes are infectious from _ to eight days.

Ex Output:
four

Ex Input:
Pelvic fins are well developed, and rather narrow, with _ to ten fin rays.

Ex Output:
nine

Ex Input:
Natural ytterbium is a mixture of _ stable isotopes, with seven other unstable isotopes known.

Ex Output:
seven