counting

Hi, Im not a developper Do you help me , i would like to: 1/first count the diffrence betwen 2 numbers in 2 variables Exemple: Var1: 30 and Var2= 5 How to have the result ? 30- 5= 25 (result) 2/After, it is possible to set the result in the"setting parameter" I want to use this result to use...

Hi everyone, I have a problem with counting class on the site in source code. For example I have on the site that line: <a class="seo-link" href="examplesite.com">Anchor</a> I don't know how I may counting quantity of class "seo-link". If the site will be two such classes I got result in...