Configuration of Router

Hi all,
I have configured three different servers with three different Classes. Letus assume ServerA ,B & C with below configarations.
Server A:
IP address 10.10.10.1
Subnet mask 255.0.0.0
Default gateway 10.10.10.10

For serverB & C the IPaddress are:10.10.10.2& 10.10.10.3. With Diffrent Subnet mask as 255.255.0.0 and 255.255.255.0.

How should a configure a router or default gateway in suchaway that all three servers should be in contact with each other?
I have configured three different routers with different IP addresses and added it in additional gateway options of Network Connections. But still the connection fails.

Thanks in advance,
Princess