using uCalcSoftware;

var uc = new uCalc();
using (var s = new uCalc.String("Some text <p>This is a paragraph.</p> more text.")) {
   
   // Extract the entire paragraph tag, including its start and end tags.
   var p_tag = s.BetweenInclusive("<p>", "</p>");

   Console.WriteLine(p_tag);
}