Specify which of these statements are functional requirements and which are

nonfunctional requirements:

$$The TicketDistributor must enable a traveler to buy weekly passes.$$

$$The TicketDistributor must be written in Java.$$

$$The TicketDistributor must be easy to use.$$

$$The TicketDistributor must always be available.$$

$$The TicketDistributor must provide a phone number to call when it fails.$$