Given the task definition, example input & output, solve the new input case.
In this task, you need to identify the sentiment of the given sentence as one of 'positive' or 'negative.
Example: tormented by the quickened blood of roots
Output: negative
There is an expression of sadness in this poem text, hence it is negative.

New input case for you: swifter far than youth's delight--
Output:
positive