c# - Split a string so that it loses http:// and anything after the '.' -

i need parse url server shows "na30" when i'm doing split cant seem na30. have tried trimming '.' , '/' , think i'm getting array parts wrong. guidance?

link https://na30.salesforce.com

what i'm working on

    string thisurl;     if (helper.instanceurl.contains(@"://"))     {         thisurl = helper.instanceurl.split(new[] { "://" }, 2, stringsplitoptions.none)[1];             return thisurl.split('/')[0].split('.')[0];     }     return ""; 

you can find string uri class

uri u = new uri("https://na30.salesforce.com"); console.writeline(u.host.split('.')[0]); 

a worth question read what's difference between uri.host , uri.authority