Heads Up :
The post you are writing will appear in a public forum. Please ensure all content is appropriate for public consumption. Review the employee guidelines for the community here.
Depends what you're trying to do but if its just a simple addressing I would just use a /28 because all you need is 14 host IPs. No subs needed.
ASR
interface GigabitEthernet0/0/5
ip address 10.0.2.1 255.255.255.240
-------------
ISRs
interface Giga...