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

Ex Input:
Humans begin laughing at _ to three months of age.

Ex Output:
two


Ex Input:
Children are almost _ times as likely to smoke if their parents do.

Ex Output:
three


Ex Input:
Tree swallows are large enough to be banded _ days after hatching.

Ex Output:

nine