That'll be two blocks: 85.206.193.0/24, 85.206.194.0/23. There should be a calculator for these things somewhere on the web ...

In this particular case, take care: a whois on 85.206.193.0 shows that the actual IP range is 85.206.192.0-85.206.207.255, or 85.206.192.0/21, which seems to be a Lithuanian Telecom range, and something about it makes me suspect it's dynamic - don't block unless you're around for a while afterwards to unblock in case of collateral damage