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

Ex Input:
Walruses walk with _ flippers over ice and snow.

Ex Output:
four

Ex Input:
Tensors have an associated rank from _ to infinity.

Ex Output:
zero

Ex Input:
Mares normally give birth to their first foal when they are between three and _ years of.

Ex Output:
six