How do I subnet this network?

I have this question that I have to answer,

There are Two networks A and B,

Ip address of A - 10.35.5.0

Ip address of B - 10.53.5.6

Each network should be able to fit 10 computers,

Suggest a suitable subnet mask,

Help!

Edit :

So the subnet I came up with is

255.128.0.0 which is wrong according to the answer sheet,

This is a class A ip address , and the answer sheet shows the answer as 255.255.255.240,

which is a class c subnetmask ,