I have a problem finding the IPs of an class in Whit i have only the netmask to start from.

this is the netmask:

<b> 255.255.255.254 <b>
I have made the following tests:

11111111 . 11111111 . 11111111 . 11111110

ok so i put it in binary and still nothing the last bit canot be changed because if it gets to be 1 then there is no net 255.255.255.255 is not valid and has no subnets. I though then thet it can be only one IP and this would be X.X.X.254 , but this is still not valid because this is the subnet.

So is anyone can help me i thanks you all in advance

PS
I'm reading a book of advance routing and subnetting and there it was this problem.
THX for your help