Confirming valid HTML tags in file using a stack C#?

Hi,

 

I have to peruse an HTML record and affirm that the majority of the HTML labels are legitimately shut utilizing a Stack to do as such. I am experiencing difficulty at the present time perusing the document and finding each tag. I don't know how I ought to continue. Should I read each line of the document, utilize regex to discover the labels, at that point add to the stack... or then again is there a superior method?